diff --git a/ecs/jskult-batch-daily/tests/testing_utility.py b/ecs/jskult-batch-daily/tests/testing_utility.py
index e95da8e7..5a6c3a42 100644
--- a/ecs/jskult-batch-daily/tests/testing_utility.py
+++ b/ecs/jskult-batch-daily/tests/testing_utility.py
@@ -1,5 +1,5 @@
-"""テスト用共通処理関数"""
 import csv
+import os
 import tempfile
 from datetime import datetime
 
@@ -22,12 +22,13 @@ def create_ultmarc_test_data_from_csv(file_path: str) -> DatFile:
     """
 
     # 一度、Shift-JISファイルで書き出す
-    with open(file_path, encoding='utf8') as csv_file, tempfile.NamedTemporaryFile('w', encoding='cp932') as tmp_file:
+    with open(file_path, encoding='utf8') as csv_file, tempfile.NamedTemporaryFile('w', encoding='cp932', delete=False) as tmp_file:
         tmp_file.write(csv_file.read())
         tmp_file.seek(0)
         tmpfile_path = tmp_file.name
-        dat_file = DatFile.from_path(tmpfile_path)
 
+    dat_file = DatFile.from_path(tmpfile_path)
+    os.unlink(tmpfile_path)
     return dat_file