A keyboard device includes at least one key and an action mechanism corresponding to the at least one key. The action mechanism includes a transmitter which moves in response to key depression to the at least one key, a hammer member which operates, in response to movement of the transmitter, to apply a load to the depressed key, a first abutting part which is arranged on one of the hammer member and a member which the hammer member abuts, and an elastic part which is arranged on another of the hammer member and the member which the hammer member abuts. At least one part of the elastic part gets over the first abutting part in a process of deforming of the elastic part, thereby a let-off feeling is given to the depressed key.