diff --git a/docs/options/options.md b/docs/options/options.md
index c3dfa04..1fc8255 100644
--- a/docs/options/options.md
+++ b/docs/options/options.md
@@ -4,6 +4,10 @@
 
 Launch as a language server.
 
+## --clear-cache
+
+Clear the cache files.
+
 ## --dump-decl
 
 Dump a type declarations file (d.er) after type checking.
diff --git a/src/config.rs b/src/config.rs
index a68ab23..2518828 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -6,6 +6,8 @@ use erg_common::config::{ErgConfig, ErgMode};
 use erg_common::io::Input;
 use erg_common::switch_lang;
 
+use crate::copy::clear_cache;
+
 fn command_message() -> &'static str {
     switch_lang!(
         "japanese" =>
@@ -21,6 +23,7 @@ OPTIONS
     --version/-V                         バージョンを表示
     --verbose 0|1|2                      冗長性レベルを指定
     --server                             Language Serverを起動
+    --clear-cache                        キャッシュをクリア
     --code/-c cmd                        文字列をプログラムに渡す
     --dump-decl                          型宣言ファイルを出力
     --disable                            指定した機能を無効化",
@@ -38,6 +41,7 @@ OPTIONS
     --version/-V                         显示版本
     --verbose 0|1|2                      指定细致程度
     --server                             启动 Language Server
+    --clear-cache                        清除缓存
     --code/-c cmd                        作为字符串传入程序
     --dump-decl                          输出类型声明文件
     --disable                            禁用指定功能",
@@ -55,6 +59,7 @@ OPTIONS
     --version/-V                         顯示版本
     --verbose 0|1|2                      指定細緻程度
     --server                             啟動 Language Server
+    --clear-cache                        清除快取
     --code/-c cmd                        作為字串傳入程式
     --dump-decl                          輸出類型宣告檔案
     --disable                            禁用指定功能",
@@ -72,6 +77,7 @@ OPTIONS
     --version/-V                         show version
     --verbose 0|1|2                      verbosity level
     --server                             start the Language Server
+    --clear-cache                        clear cache
     --code/-c cmd                        program passed in as string
     --dump-decl                          output type declaration file
     --disable                            disable specified features",
@@ -125,6 +131,10 @@ pub(crate) fn parse_args() -> ErgConfig {
                 println!("pylyzer {}", env!("CARGO_PKG_VERSION"));
                 std::process::exit(0);
             }
+            "--clear-cache" => {
+                clear_cache();
+                std::process::exit(0);
+            }
             other if other.starts_with('-') => {
                 println!(
                     "\
diff --git a/src/copy.rs b/src/copy.rs
index 5443299..2fbbad6 100644
--- a/src/copy.rs
+++ b/src/copy.rs
@@ -1,4 +1,4 @@
-use std::fs::{copy, create_dir_all, read_dir};
+use std::fs::{copy, create_dir_all, read_dir, remove_file, DirEntry};
 use std::path::Path;
 
 use erg_common::env::{erg_path, python_site_packages};
@@ -34,3 +34,50 @@ pub(crate) fn copy_dot_erg() {
         }
     }
 }
+
+pub(crate) fn clear_cache() {
+    for dir in read_dir(".").expect("Failed to read dir") {
+        let Ok(dir) = dir else {
+            continue;
+        };
+        rec_clear_cache(dir);
+    }
+    for site_packages in python_site_packages() {
+        for pkg in site_packages
+            .read_dir()
+            .expect("Failed to read site-packages")
+        {
+            let Ok(pkg) = pkg else {
+                continue;
+            };
+            rec_clear_cache(pkg);
+        }
+    }
+}
+
+fn rec_clear_cache(pkg: DirEntry) {
+    if pkg.file_type().expect("Failed to get file type").is_dir() {
+        let cache = if pkg.path().ends_with("__pycache__") {
+            pkg.path()
+        } else {
+            pkg.path().join("__pycache__")
+        };
+        if cache.exists() {
+            for cache_file in cache.read_dir().expect("Failed to read cache") {
+                let Ok(cache_file) = cache_file else {
+                    continue;
+                };
+                if cache_file.file_name().to_string_lossy().ends_with(".d.er") {
+                    println!("Removing cache file {}", cache_file.path().display());
+                    remove_file(cache_file.path()).expect("Failed to remove cache file");
+                }
+            }
+        }
+        for entry in pkg.path().read_dir().expect("Failed to read dir") {
+            let Ok(entry) = entry else {
+                continue;
+            };
+            rec_clear_cache(entry);
+        }
+    }
+}