A key structure includes, from top to bottom in sequence: at least one key main body, made of light transmissible material; a key frame, adapted to mount the key main body; an elastic supporting portion, allowing the key main bodies to move back and forth vertically; at least one bump, formed on one side of the elastic supporting portion; a detection module, sensing the action of the key main body and allowing the bump to be in touch therewith selectively; and a display screen, configured on one side of the detection module. A user can see the bottom display screen through the key main body directly, and the elastic supporting portion drives the bumps to move downward to touch the detection module after the user presses the key main body down. Whereby, the applicable range of the present invention is increased by changing the contents of the display screen.