diff --git a/finetune/tag_images_by_wd14_tagger.py b/finetune/tag_images_by_wd14_tagger.py
index 965edd7e..fbf328e8 100644
--- a/finetune/tag_images_by_wd14_tagger.py
+++ b/finetune/tag_images_by_wd14_tagger.py
@@ -160,7 +160,9 @@ def main(args):
 
     tag_freq = {}
 
-    undesired_tags = set(args.undesired_tags.split(","))
+    caption_separator = args.caption_separator
+    stripped_caption_separator = caption_separator.strip()
+    undesired_tags = set(args.undesired_tags.split(stripped_caption_separator))
 
     def run_batch(path_imgs):
         imgs = np.array([im for _, im in path_imgs])
@@ -194,7 +196,7 @@ def main(args):
 
                     if tag_name not in undesired_tags:
                         tag_freq[tag_name] = tag_freq.get(tag_name, 0) + 1
-                        general_tag_text += ", " + tag_name
+                        general_tag_text += caption_separator + tag_name
                         combined_tags.append(tag_name)
                 elif i >= len(general_tags) and p >= args.character_threshold:
                     tag_name = character_tags[i - len(general_tags)]
@@ -203,18 +205,18 @@ def main(args):
 
                     if tag_name not in undesired_tags:
                         tag_freq[tag_name] = tag_freq.get(tag_name, 0) + 1
-                        character_tag_text += ", " + tag_name
+                        character_tag_text += caption_separator + tag_name
                         combined_tags.append(tag_name)
 
             # 先頭のカンマを取る
             if len(general_tag_text) > 0:
-                general_tag_text = general_tag_text[2:]
+                general_tag_text = general_tag_text[len(caption_separator) :]
             if len(character_tag_text) > 0:
-                character_tag_text = character_tag_text[2:]
+                character_tag_text = character_tag_text[len(caption_separator) :]
 
             caption_file = os.path.splitext(image_path)[0] + args.caption_extension
 
-            tag_text = ", ".join(combined_tags)
+            tag_text = caption_separator.join(combined_tags)
 
             if args.append_tags:
                 # Check if file exists
@@ -224,13 +226,13 @@ def main(args):
                         existing_content = f.read().strip("\n")  # Remove newlines
 
                     # Split the content into tags and store them in a list
-                    existing_tags = [tag.strip() for tag in existing_content.split(",") if tag.strip()]
+                    existing_tags = [tag.strip() for tag in existing_content.split(stripped_caption_separator) if tag.strip()]
 
                     # Check and remove repeating tags in tag_text
                     new_tags = [tag for tag in combined_tags if tag not in existing_tags]
 
                     # Create new tag_text
-                    tag_text = ", ".join(existing_tags + new_tags)
+                    tag_text = caption_separator.join(existing_tags + new_tags)
 
             with open(caption_file, "wt", encoding="utf-8") as f:
                 f.write(tag_text + "\n")
@@ -350,6 +352,12 @@ def setup_parser() -> argparse.ArgumentParser:
     parser.add_argument("--frequency_tags", action="store_true", help="Show frequency of tags for images / 画像ごとのタグの出現頻度を表示する")
     parser.add_argument("--onnx", action="store_true", help="use onnx model for inference / onnxモデルを推論に使用する")
     parser.add_argument("--append_tags", action="store_true", help="Append captions instead of overwriting / 上書きではなくキャプションを追記する")
+    parser.add_argument(
+        "--caption_separator",
+        type=str,
+        default=", ",
+        help="Separator for captions, include space if needed / キャプションの区切り文字、必要ならスペースを含めてください",
+    )
 
     return parser