diff --git a/popcorn/Assets/MyGame/Scripts/CoinManager.cs b/popcorn/Assets/MyGame/Scripts/CoinManager.cs
index d925aa9a..dd1c5c75 100644
--- a/popcorn/Assets/MyGame/Scripts/CoinManager.cs
+++ b/popcorn/Assets/MyGame/Scripts/CoinManager.cs
@@ -40,7 +40,7 @@ public class CoinManager : SingletonMonoBehaviour<CoinManager>
         coinCountText.CountUpAnimation(coinTextFormat, ownCoin, duration);
     }
 
-    public void AddCoinWithEffect(int count, Action callback)
+    public void AddCoinWithEffect(int count, Action callback = null)
     {
         ownCoin += count;
         // 生成枚数決定
@@ -48,7 +48,7 @@ public class CoinManager : SingletonMonoBehaviour<CoinManager>
         InstantiateEffeect(coinPrefab, count, Vector3.zero, coinIconTransform.position, () =>
         {
             coinCountText.CountUpAnimation(coinTextFormat, ownCoin, duration);
-            callback.Invoke();
+            callback?.Invoke();
         });
     }