A key input device combined with a key display unit and a digital
appliance having the same are disclosed. The key input device includes a
key display unit for displaying a character or an image that identifies a
key, a touch sensing unit that moves down and up by a pressure applied to
this key, and a signal generation unit for generating an electric signal
in accordance with the pressure applied to the key, wherein the character
or the image displayed on the key display unit can be changed.