Keyboard device

A keyboard device for an electronic device, the keyboard device comprising:

• a keyboard main body;
• and
• a protection plate member pivotally coupled to the keyboard main body, wherein the protection plate member is rotatable relative to the keyboard main body, so that the keyboard main body is covered by the protection plate member or a first angle is formed between the protection plate member and the keyboard main body, wherein the protection plate member comprises a first plate and a second plate, the keyboard main body is pivotally coupled to a first end of the first plate, the second plate is pivotally coupled to a second end of the first plate, the first end and the second end of the first plate are opposed to each other, and the second plate is rotatable relative to the first plate,
• wherein after the protection plate member is rotated relative to the keyboard main body and the first angle is formed between the protection plate member and the keyboard main body, the protection plate member is further adjusted to a selected usage mode of plural usage modes, and the electronic device is supported by the first plate or the second plate of the protection plate member in the selected usage mode.