diff --git a/Assets/VRM10/Editor/MigrationMenu.cs b/Assets/VRM10/Editor/MigrationMenu.cs
deleted file mode 100644
index d497f79a8..000000000
--- a/Assets/VRM10/Editor/MigrationMenu.cs
+++ /dev/null
@@ -1,56 +0,0 @@
-using System.IO;
-using UnityEditor;
-using UnityEngine;
-
-namespace UniVRM10
-{
-    public static class MigrationMenu
-    {
-        static VRMShaders.PathObject s_lastPath = VRMShaders.PathObject.UnityAssets;
-
-        const string CONTEXT_MENU = "Assets/Migration: Vrm1";
-
-        [MenuItem(CONTEXT_MENU, true)]
-        static bool Enable()
-        {
-            if (!VRMShaders.PathObject.TryGetFromAsset(Selection.activeObject, out VRMShaders.PathObject path))
-            {
-                return false;
-            }
-            var isVrm = path.Extension.ToLower() == ".vrm";
-            return isVrm;
-        }
-
-        [MenuItem(CONTEXT_MENU, false)]
-        static void Exec()
-        {
-            if (!VRMShaders.PathObject.TryGetFromAsset(Selection.activeObject, out VRMShaders.PathObject path))
-            {
-                return;
-            }
-
-            // migrate
-            var vrm1Bytes = MigrationVrm.Migrate(path.ReadAllBytes());
-
-            if (!s_lastPath.TrySaveDialog("Save vrm1 file", $"{path.Stem}_vrm1", out VRMShaders.PathObject dst))
-            {
-                return;
-            }
-            s_lastPath = dst.Parent;
-
-            // write result
-            dst.WriteAllBytes(vrm1Bytes);
-
-            if (dst.IsUnderAsset)
-            {
-                // immediately import for GUI update
-                Debug.Log($"import: {dst}");
-                dst.ImportAsset();
-            }
-            else
-            {
-                Debug.Log($"write: {dst}");
-            }
-        }
-    }
-}
diff --git a/Assets/VRM10/Editor/MigrationMenu.cs.meta b/Assets/VRM10/Editor/MigrationMenu.cs.meta
deleted file mode 100644
index cc4e4ebc9..000000000
--- a/Assets/VRM10/Editor/MigrationMenu.cs.meta
+++ /dev/null
@@ -1,11 +0,0 @@
-fileFormatVersion: 2
-guid: c0be718f3aba6ad4282a4b74eae9045b
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: