diff --git a/dictation_client/src/AppRouter.tsx b/dictation_client/src/AppRouter.tsx
index 7510a67..cc6ce15 100644
--- a/dictation_client/src/AppRouter.tsx
+++ b/dictation_client/src/AppRouter.tsx
@@ -4,6 +4,7 @@ import TopPage from "pages/TopPage";
 import LoginPage from "pages/LoginPage";
 import SamplePage from "pages/SamplePage";
 import { AuthErrorPage } from "pages/ErrorPage";
+import { NotFoundPage } from "pages/ErrorPage/notFound";
 import { RouteAuthGuard } from "components/auth/routeAuthGuard";
 
 const AppRouter: React.FC = () => (
@@ -16,6 +17,7 @@ const AppRouter: React.FC = () => (
         path="/XXX"
         element={<RouteAuthGuard component={<SamplePage />} />}
       />
+      <Route path="*" element={<NotFoundPage />} />
     </Routes>
   </BaseDiv>
 );
diff --git a/dictation_client/src/pages/ErrorPage/notFound.tsx b/dictation_client/src/pages/ErrorPage/notFound.tsx
new file mode 100644
index 0000000..dd079e0
--- /dev/null
+++ b/dictation_client/src/pages/ErrorPage/notFound.tsx
@@ -0,0 +1,9 @@
+import React from "react";
+
+export const NotFoundPage = (): JSX.Element => (
+  <div>
+    <p>404 Not Found</p>
+    <p>ページが見つかりませんでした</p>
+    <br />
+  </div>
+);