The present invention relates to a keyboard, including a first baseboard, a second baseboard, a deformation element, a key cap, and a connecting element. The deformation element is disposed between the first baseboard and the second baseboard and is capable of deforming according to a received voltage signal. The deformation element drags the second baseboard to move in a first direction when the deformation element receives the voltage signal and therefore deforms to be in an extended state, so that the key cap is at a first height. The deformation element pushes the second baseboard to move in a second direction when the deformation element does not receive the voltage signal and therefore deforms to be in a bent state, so that the key cap is at a relatively shorter second height.