diff --git a/library/train_util.py b/library/train_util.py
index b8feac74..b06caf3d 100644
--- a/library/train_util.py
+++ b/library/train_util.py
@@ -2745,15 +2745,19 @@ def prepare_accelerator(args: argparse.Namespace):
         log_prefix = "" if args.log_prefix is None else args.log_prefix
         logging_dir = args.logging_dir + "/" + log_prefix + time.strftime("%Y%m%d%H%M%S", time.localtime())
 
-    log_with = "tensorboard" if args.log_with is None else args.log_with
-    if log_with in ["wandb", "all"]:
-        if logging_dir is not None:
-            os.makedirs(logging_dir)
-            os.environ["WANDB_DIR"] = logging_dir
-        try:
-            import wandb
-        except ImportError:
-            raise ImportError("No wandb / wandb がインストールされていないようです")
+    if args.log_with is not None:
+        log_with = "tensorboard" if args.log_with is None else args.log_with
+        if log_with in ["tensorboard", "all"]:
+            if logging_dir is None:
+                raise ValueError("logging_dir is required when log_with is tensorboard / Tensorboardを使う場合、logging_dirを指定してください")
+        if log_with in ["wandb", "all"]:
+            try:
+                import wandb
+            except ImportError:
+                raise ImportError("No wandb / wandb がインストールされていないようです")
+            if logging_dir is not None:
+                os.makedirs(logging_dir)
+                os.environ["WANDB_DIR"] = logging_dir
 
     accelerator = Accelerator(
         gradient_accumulation_steps=args.gradient_accumulation_steps,