diff --git a/scripts/fetch_and_generate.ts b/scripts/fetch_and_generate.ts
index ba69719..6aae1e3 100644
--- a/scripts/fetch_and_generate.ts
+++ b/scripts/fetch_and_generate.ts
@@ -82,9 +82,9 @@ async function main() {
       .createHash("md5")
       .update(category)
       .digest("hex");
-    const uniqueFilename = `${feedUrlHash}-${categoryHash}.wav`;
+    const uniqueId = `${feedUrlHash}-${categoryHash}.wav`;
 
-    const audioFilePath = await generateTTS(uniqueFilename, podcastContent);
+    const audioFilePath = await generateTTS(uniqueId, podcastContent);
     console.log(`音声ファイル生成完了: ${audioFilePath}`);
 
     // エピソードとして保存（各フィードにつき1つの統合エピソード）
@@ -96,7 +96,7 @@ async function main() {
     const pub = new Date(firstItem.pubDate || "");
 
     await saveEpisode({
-      id: `topic-${categoryHash}`,
+      id: uniqueId,
       title: `${category}: ${feedTitle}`,
       pubDate: pub.toISOString(),
       audioPath: audioFilePath,
diff --git a/services/tts.ts b/services/tts.ts
index 470748a..419e07f 100644
--- a/services/tts.ts
+++ b/services/tts.ts
@@ -63,7 +63,7 @@ export async function generateTTS(
 
   const filePath = path.resolve(outputDir, itemId); // Use the provided filename directly
   console.log(`音声ファイル保存開始: ${filePath}`);
-  fs.writeFileSync(filePath, audioBuffer);
+  fs.writeFileSync(`${filePath}.wav`, audioBuffer);
   console.log(`音声ファイル保存完了: ${filePath}`);
 
   return path.basename(filePath);