diff --git a/dictation_server/src/features/auth/auth.controller.ts b/dictation_server/src/features/auth/auth.controller.ts
index 0418584..a07b666 100644
--- a/dictation_server/src/features/auth/auth.controller.ts
+++ b/dictation_server/src/features/auth/auth.controller.ts
@@ -32,7 +32,7 @@ import { AuthGuard } from '../../common/guards/auth/authguards';
 import { RoleGuard } from '../../common/guards/role/roleguards';
 import { ADMIN_ROLES, TIERS } from '../../constants';
 import jwt from 'jsonwebtoken';
-import { AccessToken } from '../../common/token';
+import { AccessToken, RefreshToken } from '../../common/token';
 
 @ApiTags('auth')
 @Controller('auth')
@@ -248,9 +248,23 @@ export class AuthController {
         HttpStatus.UNAUTHORIZED,
       );
     }
+    const decodedRefreshToken = jwt.decode(refreshToken, { json: true });
+    if (!decodedRefreshToken) {
+      throw new HttpException(
+        makeErrorResponse('E000101'),
+        HttpStatus.UNAUTHORIZED,
+      );
+    }
+    const { userId, delegateUserId } = decodedRefreshToken as RefreshToken;
 
-    const context = makeContext(uuidv4());
+    const context = makeContext(userId);
+    const accessToken = await this.authService.updateDelegationAccessToken(
+      context,
+      delegateUserId,
+      userId,
+      refreshToken,
+    );
 
-    return { accessToken: '' };
+    return { accessToken };
   }
 }
diff --git a/dictation_server/src/features/auth/auth.service.spec.ts b/dictation_server/src/features/auth/auth.service.spec.ts
index bcb5324..1be5e40 100644
--- a/dictation_server/src/features/auth/auth.service.spec.ts
+++ b/dictation_server/src/features/auth/auth.service.spec.ts
@@ -9,9 +9,13 @@ import {
 import { DataSource } from 'typeorm';
 import { makeContext } from '../../common/log';
 import { makeTestingModule } from '../../common/test/modules';
-import { makeTestAccount } from '../../common/test/utility';
+import { getAccount, makeTestAccount } from '../../common/test/utility';
 import { AuthService } from './auth.service';
-import { createTermInfo } from './test/utility';
+import {
+  createTermInfo,
+  deleteAccount,
+  updateAccountDelegationPermission,
+} from './test/utility';
 import { v4 as uuidv4 } from 'uuid';
 import { TIERS, USER_ROLES } from '../../constants';
 import { decode, isVerifyError } from '../../common/jwt';
@@ -512,6 +516,214 @@ describe('generateDelegationAccessToken', () => {
   });
 });
 
+describe('updateDelegationAccessToken', () => {
+  let source: DataSource | null = null;
+  beforeEach(async () => {
+    source = new DataSource({
+      type: 'sqlite',
+      database: ':memory:',
+      logging: false,
+      entities: [__dirname + '/../../**/*.entity{.ts,.js}'],
+      synchronize: true, // trueにすると自動的にmigrationが行われるため注意
+    });
+    return source.initialize();
+  });
+
+  afterEach(async () => {
+    if (!source) return;
+    await source.destroy();
+    source = null;
+  });
+
+  it('代行操作用リフレッシュトークンから代行操作用アクセストークンを更新できること', async () => {
+    if (!source) fail();
+    const module = await makeTestingModule(source);
+    if (!module) fail();
+    const service = module.get<AuthService>(AuthService);
+    const { admin: parentAdmin, account: parentAccount } =
+      await makeTestAccount(source, {
+        tier: 4,
+      });
+    const { admin: partnerAdmin, account: partnerAccount } =
+      await makeTestAccount(
+        source,
+        {
+          tier: 5,
+          parent_account_id: parentAccount.id,
+          delegation_permission: true,
+        },
+        { role: USER_ROLES.NONE },
+      );
+
+    const context = makeContext(parentAdmin.external_id);
+
+    const delegationRefreshToken = await service.generateDelegationRefreshToken(
+      context,
+      parentAdmin.external_id,
+      partnerAccount.id,
+    );
+
+    // 取得できた代行操作用リフレッシュトークンをデコード
+    const decodeRefreshToken = decode<RefreshToken>(delegationRefreshToken);
+    if (isVerifyError(decodeRefreshToken)) {
+      fail();
+    }
+
+    expect(decodeRefreshToken.role).toBe('none admin');
+    expect(decodeRefreshToken.tier).toBe(TIERS.TIER5);
+    expect(decodeRefreshToken.userId).toBe(partnerAdmin.external_id);
+    expect(decodeRefreshToken.delegateUserId).toBe(parentAdmin.external_id);
+
+    const token = await service.updateDelegationAccessToken(
+      context,
+      decodeRefreshToken.delegateUserId,
+      decodeRefreshToken.userId,
+      delegationRefreshToken,
+    );
+
+    // 取得できた代行操作用リフレッシュトークンをデコード
+    const decodeAccessToken = decode<RefreshToken>(token);
+    if (isVerifyError(decodeAccessToken)) {
+      fail();
+    }
+
+    expect(decodeAccessToken.role).toBe('none admin');
+    expect(decodeAccessToken.tier).toBe(TIERS.TIER5);
+    expect(decodeAccessToken.userId).toBe(partnerAdmin.external_id);
+    expect(decodeAccessToken.delegateUserId).toBe(parentAdmin.external_id);
+  });
+
+  it('代行操作対象アカウントの代行操作が許可されていない場合、エラーとなること', async () => {
+    if (!source) fail();
+    const module = await makeTestingModule(source);
+    if (!module) fail();
+    const service = module.get<AuthService>(AuthService);
+    const { admin: parentAdmin, account: parentAccount } =
+      await makeTestAccount(source, {
+        tier: 4,
+      });
+    const { admin: partnerAdmin, account: partnerAccount } =
+      await makeTestAccount(
+        source,
+        {
+          tier: 5,
+          parent_account_id: parentAccount.id,
+          delegation_permission: true,
+        },
+        { role: USER_ROLES.NONE },
+      );
+
+    const context = makeContext(parentAdmin.external_id);
+
+    const delegationRefreshToken = await service.generateDelegationRefreshToken(
+      context,
+      parentAdmin.external_id,
+      partnerAccount.id,
+    );
+
+    // 取得できた代行操作用リフレッシュトークンをデコード
+    const decodeRefreshToken = decode<RefreshToken>(delegationRefreshToken);
+    if (isVerifyError(decodeRefreshToken)) {
+      fail();
+    }
+
+    expect(decodeRefreshToken.role).toBe('none admin');
+    expect(decodeRefreshToken.tier).toBe(TIERS.TIER5);
+    expect(decodeRefreshToken.userId).toBe(partnerAdmin.external_id);
+    expect(decodeRefreshToken.delegateUserId).toBe(parentAdmin.external_id);
+
+    if (decodeRefreshToken.delegateUserId === undefined) {
+      fail();
+    }
+
+    // 代行操作対象アカウントの代行操作を許可しないように変更
+    await updateAccountDelegationPermission(source, partnerAccount.id, false);
+    const account = await getAccount(source, partnerAccount.id);
+
+    expect(account?.delegation_permission ?? true).toBeFalsy();
+
+    try {
+      await service.updateDelegationAccessToken(
+        context,
+        decodeRefreshToken.delegateUserId,
+        decodeRefreshToken.userId,
+        delegationRefreshToken,
+      );
+      fail();
+    } catch (e) {
+      if (e instanceof HttpException) {
+        expect(e.getStatus()).toEqual(HttpStatus.UNAUTHORIZED);
+        expect(e.getResponse()).toEqual(makeErrorResponse('E010503'));
+      } else {
+        fail();
+      }
+    }
+  });
+  it('代行操作対象アカウントが存在しない場合、エラーとなること', async () => {
+    if (!source) fail();
+    const module = await makeTestingModule(source);
+    if (!module) fail();
+    const service = module.get<AuthService>(AuthService);
+    const { admin: parentAdmin, account: parentAccount } =
+      await makeTestAccount(source, {
+        tier: 4,
+      });
+    const { admin: partnerAdmin, account: partnerAccount } =
+      await makeTestAccount(
+        source,
+        {
+          tier: 5,
+          parent_account_id: parentAccount.id,
+          delegation_permission: true,
+        },
+        { role: USER_ROLES.NONE },
+      );
+
+    const context = makeContext(parentAdmin.external_id);
+
+    const delegationRefreshToken = await service.generateDelegationRefreshToken(
+      context,
+      parentAdmin.external_id,
+      partnerAccount.id,
+    );
+
+    // 取得できた代行操作用リフレッシュトークンをデコード
+    const decodeRefreshToken = decode<RefreshToken>(delegationRefreshToken);
+    if (isVerifyError(decodeRefreshToken)) {
+      fail();
+    }
+
+    expect(decodeRefreshToken.role).toBe('none admin');
+    expect(decodeRefreshToken.tier).toBe(TIERS.TIER5);
+    expect(decodeRefreshToken.userId).toBe(partnerAdmin.external_id);
+    expect(decodeRefreshToken.delegateUserId).toBe(parentAdmin.external_id);
+
+    if (decodeRefreshToken.delegateUserId === undefined) {
+      fail();
+    }
+
+    // 代行操作対象アカウントを削除
+    deleteAccount(source, partnerAccount.id);
+
+    try {
+      await service.updateDelegationAccessToken(
+        context,
+        decodeRefreshToken.delegateUserId,
+        partnerAdmin.external_id,
+        delegationRefreshToken,
+      );
+      fail();
+    } catch (e) {
+      if (e instanceof HttpException) {
+        expect(e.getStatus()).toEqual(HttpStatus.UNAUTHORIZED);
+        expect(e.getResponse()).toEqual(makeErrorResponse('E010501'));
+      } else {
+        fail();
+      }
+    }
+  });
+});
+
 const idTokenPayload = {
   exp: 9000000000,
   nbf: 1000000000,
diff --git a/dictation_server/src/features/auth/auth.service.ts b/dictation_server/src/features/auth/auth.service.ts
index 3e2a9cc..23ba89b 100644
--- a/dictation_server/src/features/auth/auth.service.ts
+++ b/dictation_server/src/features/auth/auth.service.ts
@@ -25,8 +25,15 @@ import {
   AccountNotFoundError,
   AdminUserNotFoundError,
 } from '../../repositories/accounts/errors/types';
-import { DelegationNotAllowedError } from '../../repositories/users/errors/types';
-import { RoleUnexpectedError, TierUnexpectedError } from './errors/types';
+import {
+  DelegationNotAllowedError,
+  UserNotFoundError,
+} from '../../repositories/users/errors/types';
+import {
+  InvalidTokenFormatError,
+  RoleUnexpectedError,
+  TierUnexpectedError,
+} from './errors/types';
 
 @Injectable()
 export class AuthService {
@@ -328,6 +335,116 @@ export class AuthService {
     return accessToken;
   }
 
+  /**
+   * 代行操作用アクセストークンを更新する
+   * @param context
+   * @param delegateUserExternalId
+   * @param originUserExternalId
+   * @param refreshToken
+   * @returns delegation access token
+   */
+  async updateDelegationAccessToken(
+    context: Context,
+    delegateUserExternalId: string | undefined,
+    originUserExternalId: string,
+    refreshToken: string,
+  ): Promise<string> {
+    this.logger.log(
+      `[IN] [${context.trackingId}] ${this.updateDelegationAccessToken.name} | params: { ` +
+        `delegateUserExternalId: ${delegateUserExternalId}, ` +
+        `originUserExternalId: ${originUserExternalId}, };`,
+    );
+    try {
+      if (!delegateUserExternalId) {
+        throw new UserNotFoundError('delegateUserExternalId is undefined');
+      }
+
+      const user = await this.usersRepository.findUserByExternalId(
+        delegateUserExternalId,
+      );
+
+      const privateKey = getPrivateKey(this.configService);
+      const pubkey = getPublicKey(this.configService);
+
+      // トークンの検証
+      const decodedToken = verify<RefreshToken>(refreshToken, pubkey);
+      if (isVerifyError(decodedToken)) {
+        throw new InvalidTokenFormatError(
+          `Invalid token format. ${decodedToken.reason} | ${decodedToken.message}`,
+        );
+      }
+
+      // トークンの生成には検証済みトークンの値を使用する
+      const { userId, delegateUserId, tier, role } = decodedToken;
+
+      if (delegateUserId === undefined) {
+        throw new AdminUserNotFoundError('delegateUserId is undefined');
+      }
+
+      // 代行操作対象アカウントの管理者ユーザーが存在して、アカウントに対して代行操作権限があるか確認
+      const delegationPermission =
+        await this.usersRepository.isAllowDelegationPermission(
+          user.account_id,
+          userId,
+        );
+
+      if (!delegationPermission) {
+        throw new DelegationNotAllowedError(
+          `Delegation is not allowed. delegateUserId=${delegateUserId}, userId=${userId}`,
+        );
+      }
+
+      const accessToken = sign<AccessToken>(
+        {
+          role: role,
+          tier: tier,
+          userId: userId,
+          delegateUserId: delegateUserId,
+        },
+        this.accessTokenlifetime,
+        privateKey,
+      );
+
+      return accessToken;
+    } catch (e) {
+      this.logger.error(`error=${e}`);
+      if (e instanceof HttpException) {
+        throw e;
+      }
+      if (e instanceof Error) {
+        switch (e.constructor) {
+          case InvalidTokenFormatError:
+            throw new HttpException(
+              makeErrorResponse('E000101'),
+              HttpStatus.UNAUTHORIZED,
+            );
+          case UserNotFoundError:
+          case AccountNotFoundError:
+          case AdminUserNotFoundError:
+            throw new HttpException(
+              makeErrorResponse('E010501'),
+              HttpStatus.UNAUTHORIZED,
+            );
+          case DelegationNotAllowedError:
+            throw new HttpException(
+              makeErrorResponse('E010503'),
+              HttpStatus.UNAUTHORIZED,
+            );
+          default:
+            break;
+        }
+      }
+      throw new HttpException(
+        makeErrorResponse('E009999'),
+        HttpStatus.INTERNAL_SERVER_ERROR,
+      );
+    } finally {
+      this.logger.log(
+        `[OUT] [${context.trackingId}] ${this.updateDelegationAccessToken.name}`,
+      );
+    }
+  }
+
   /**
    * Gets id token
    * @param token
diff --git a/dictation_server/src/features/auth/errors/types.ts b/dictation_server/src/features/auth/errors/types.ts
index 5c12d36..969d13a 100644
--- a/dictation_server/src/features/auth/errors/types.ts
+++ b/dictation_server/src/features/auth/errors/types.ts
@@ -2,3 +2,5 @@
 export class RoleUnexpectedError extends Error {}
 // Tier範囲想定外エラー
 export class TierUnexpectedError extends Error {}
+// トークン形式不正エラー
+export class InvalidTokenFormatError extends Error {}
diff --git a/dictation_server/src/features/auth/test/utility.ts b/dictation_server/src/features/auth/test/utility.ts
index c5c2c51..fbbc0e4 100644
--- a/dictation_server/src/features/auth/test/utility.ts
+++ b/dictation_server/src/features/auth/test/utility.ts
@@ -1,5 +1,7 @@
 import { DataSource } from 'typeorm';
 import { Term } from '../../../repositories/terms/entity/term.entity';
+import { Account } from '../../../repositories/accounts/entity/account.entity';
+import { User } from '../../../repositories/users/entity/user.entity';
 
 export const createTermInfo = async (
   datasource: DataSource,
@@ -16,3 +18,21 @@ export const createTermInfo = async (
   });
   identifiers.pop() as Term;
 };
+
+export const updateAccountDelegationPermission = async (
+  dataSource: DataSource,
+  id: number,
+  delegationPermission: boolean,
+): Promise<void> => {
+  await dataSource
+    .getRepository(Account)
+    .update({ id: id }, { delegation_permission: delegationPermission });
+};
+
+export const deleteAccount = async (
+  dataSource: DataSource,
+  id: number,
+): Promise<void> => {
+  await dataSource.getRepository(User).delete({ account_id: id });
+  await dataSource.getRepository(Account).delete({ id: id });
+};
diff --git a/dictation_server/src/features/files/files.service.ts b/dictation_server/src/features/files/files.service.ts
index 96ac698..44dff8f 100644
--- a/dictation_server/src/features/files/files.service.ts
+++ b/dictation_server/src/features/files/files.service.ts
@@ -1,6 +1,5 @@
 import { HttpException, HttpStatus, Injectable, Logger } from '@nestjs/common';
 import { makeErrorResponse } from '../../common/error/makeErrorResponse';
-import { AccessToken } from '../../common/token';
 import { UsersRepositoryService } from '../../repositories/users/users.repository.service';
 import { TasksRepositoryService } from '../../repositories/tasks/tasks.repository.service';
 import { BlobstorageService } from '../../gateways/blobstorage/blobstorage.service';
diff --git a/dictation_server/src/repositories/users/users.repository.service.ts b/dictation_server/src/repositories/users/users.repository.service.ts
index 7f92ae3..8a43aad 100644
--- a/dictation_server/src/repositories/users/users.repository.service.ts
+++ b/dictation_server/src/repositories/users/users.repository.service.ts
@@ -601,4 +601,47 @@ export class UsersRepositoryService {
       return primaryUser;
     });
   }
+
+  /**
+   * 代行操作対象のユーザーの所属するアカウントの代行操作が許可されているか
+   * @param delegateAccountId 代行操作者のアカウントID
+   * @param originAccountId 代行操作対象のアカウントID
+   * @returns delegate accounts
+   */
+  async isAllowDelegationPermission(
+    delegateAccountId: number,
+    originUserExternalId: string,
+  ): Promise<boolean> {
+    return await this.dataSource.transaction(async (entityManager) => {
+      const userRepo = entityManager.getRepository(User);
+      const primaryUser = await userRepo.findOne({
+        where: {
+          external_id: originUserExternalId,
+          account: {
+            parent_account_id: delegateAccountId,
+            tier: TIERS.TIER5,
+          },
+        },
+        relations: {
+          account: true,
+        },
+      });
+
+      if (!primaryUser) {
+        throw new AdminUserNotFoundError(
+          `Admin user is not found. externalId: ${originUserExternalId}`,
+        );
+      }
+
+      const originAccount = primaryUser.account;
+
+      // 運用上、アカウントがいないことはあり得ないが、プログラム上発生しうるのでエラーとして処理
+      if (!originAccount) {
+        throw new Error(`Account is Not Found. id: ${primaryUser.account_id}`);
+      }
+
+      // 代行操作の許可の有無を返却
+      return originAccount.delegation_permission;
+    });
+  }
 }