diff --git a/keyboard/KeyboardViewController.swift b/keyboard/KeyboardViewController.swift
index 18fcf18..140f8a8 100644
--- a/keyboard/KeyboardViewController.swift
+++ b/keyboard/KeyboardViewController.swift
@@ -94,11 +94,27 @@ class KeyboardViewController: UIInputViewController, FcitxProtocol {
   }
 
   public func keyPressed(_ key: String) {
-    if !processKey(key) {
+    var finalKey = key
+    // Handle special keys
+    if key == "BackSpace" {
+      // backspace
+      processBackspace()
+      return
+    }
+
+    // Handle normal keys and other symbols
+    if !processKey(finalKey) {
       textDocumentProxy.insertText(key)
     }
   }
 
+  private func processBackspace() {
+    if !processKey("BackSpace") {
+      // Fallback to the default behavior
+      textDocumentProxy.deleteBackward()
+    }
+  }
+
   public func commitString(_ commit: String) {
     textDocumentProxy.insertText(commit)
   }
diff --git a/keyboard/fcitx.cpp b/keyboard/fcitx.cpp
index 4af7a48..1b91287 100644
--- a/keyboard/fcitx.cpp
+++ b/keyboard/fcitx.cpp
@@ -28,8 +28,9 @@ void focusOut() {
 }
 
 bool processKey(const char *key) {
-    return with_fcitx(
-        [key] { return frontend->keyEvent(fcitx::Key{key}, false); });
+    return with_fcitx([key] {
+        return frontend->keyEvent(fcitx::Key{key}, false);
+    });
 }
 
 void reload() {
diff --git a/uipanel/CMakeLists.txt b/uipanel/CMakeLists.txt
index bd7f37e..9c776a4 100644
--- a/uipanel/CMakeLists.txt
+++ b/uipanel/CMakeLists.txt
@@ -1,6 +1,7 @@
 add_library(KeyboardUI STATIC
     keyboardui.swift
     Key.swift
+    KeyAction.swift
     Keyboard.swift
     Candidate.swift
     CandidateBar.swift
diff --git a/uipanel/Key.swift b/uipanel/Key.swift
index 7590616..275844a 100644
--- a/uipanel/Key.swift
+++ b/uipanel/Key.swift
@@ -3,9 +3,11 @@ import UIKit
 
 class Key: UIButton {
   let client: FcitxProtocol
+  let action: KeyAction
 
-  init(_ client: FcitxProtocol, _ label: String) {
+  init(_ client: FcitxProtocol, _ label: String, _ action: KeyAction) {
     self.client = client
+    self.action = action
     super.init(frame: .zero)
     setTitle(label, for: .normal)
     titleLabel?.font = UIFont.systemFont(ofSize: 24)
@@ -22,6 +24,6 @@ class Key: UIButton {
     guard let currentTitle = sender.currentTitle else {
       return
     }
-    client.keyPressed(currentTitle)
+    self.action.perform(self.client)
   }
 }
diff --git a/uipanel/KeyAction.swift b/uipanel/KeyAction.swift
new file mode 100644
index 0000000..cee954c
--- /dev/null
+++ b/uipanel/KeyAction.swift
@@ -0,0 +1,78 @@
+import FcitxProtocol
+
+class KeyAction {
+  var key: String
+  var capsKey: String
+  var label: String
+  var capsLabel: String
+  var action: (_ client: FcitxProtocol) -> Void
+
+  init(key: String, capsKey: String, label: String, capsLabel: String, action: @escaping (_ client: FcitxProtocol) -> Void) {
+    self.key = key
+    self.capsKey = capsKey
+    self.label = label
+    self.capsLabel = capsLabel
+    self.action = action
+  }
+
+  convenience init(key: String, capsKey: String, action: @escaping (_ client: FcitxProtocol) -> Void) {
+    self.init(key: key, capsKey: capsKey, label: key, capsLabel: capsKey, action: action)
+  }
+
+  convenience init(key: String, label: String, action: @escaping (_ client: FcitxProtocol) -> Void) {
+    self.init(key: key, capsKey: key, label: label, capsLabel: label, action: action)
+  }
+
+  convenience init(key: String, action: @escaping (_ client: FcitxProtocol) -> Void) {
+    self.init(key: key, capsKey: key, action: action)
+  }
+
+  func perform(_ client: FcitxProtocol) {
+    self.action(client)
+  }
+}
+
+class AlphabetKeyAction: KeyAction {
+  init(key: String) {
+    super.init(
+      key: key,
+      capsKey: key.uppercased(),
+      label: key,
+      capsLabel: key.uppercased(),
+      action: { client in
+        client.keyPressed(key)
+      })
+  }
+}
+
+class SymbolKeyAction: KeyAction {
+  init(symbol: String, label: String) {
+    // Use the symbol name of keyNameList in `fcitx5/src/lib/fcitx-utils/keynametable.h`
+    super.init(
+      key: symbol,
+      capsKey: symbol,
+      label: label,
+      capsLabel: label,
+      action: { client in
+        client.keyPressed(symbol)
+      })
+  }
+}
+
+class BackspaceKeyAction: SymbolKeyAction {
+  init() {
+    super.init(symbol: "BackSpace", label: "⌫")
+  }
+}
+
+class InternalStateKeyAction: KeyAction {
+  init(label: String, action: @escaping (_ client: FcitxProtocol) -> Void) {
+    super.init(
+      key: label,
+      capsKey: label,
+      label: label,
+      capsLabel: label,
+      action: action
+    )
+  }
+}
diff --git a/uipanel/Keyboard.swift b/uipanel/Keyboard.swift
index 23e370d..f9ac1c3 100644
--- a/uipanel/Keyboard.swift
+++ b/uipanel/Keyboard.swift
@@ -8,8 +8,8 @@ class Keyboard: UIStackView {
     ["1", "2", "3", "4", "5", "6", "7", "8", "9", "0"],
     ["q", "w", "e", "r", "t", "y", "u", "i", "o", "p"],
     ["a", "s", "d", "f", "g", "h", "j", "k", "l"],
-    ["`", "z", "x", "c", "v", "b", "n", "m"],
-    [",", " ", "."],
+    ["Shift", "`", "z", "x", "c", "v", "b", "n", "m", "⌫"],
+    [",", "🌐", " ", "."],
   ]
 
   init(_ client: FcitxProtocol) {
@@ -36,7 +36,26 @@ class Keyboard: UIStackView {
       rowStackView.spacing = 5
 
       for key in row {
-        let button = Key(client, key)
+        // TODO(Inoki): find a better way to handle special keys
+        if key == "⌫" {
+          let button = Key(client, key, BackspaceKeyAction())
+          rowStackView.addArrangedSubview(button)
+          continue
+        } else if key == "🌐" {
+          let button = Key(client, key, InternalStateKeyAction(label: key, action: { client in
+            // TODO: switch keyboard
+          }))
+          rowStackView.addArrangedSubview(button)
+          continue
+        } else if key == "Shift" {
+          let button = Key(client, "⇧", InternalStateKeyAction(label: key, action: { client in
+            // TODO: switch keyboard
+          }))
+          rowStackView.addArrangedSubview(button)
+          continue
+        }
+
+        let button = Key(client, key, AlphabetKeyAction(key: key))
         rowStackView.addArrangedSubview(button)
       }
       addArrangedSubview(rowStackView)