A keyboard device includes plural white and black keys 11w, 11b that rock according to a key depression/release operation. Positions of key support portions 13w, 13b supporting the plural white and black keys 11w, 11b in the longitudinal direction are set to be different from one another. The keyboard device also includes hammers 16w, 16b that rock with the rocking movement of the plural white and black keys 11w, 11b. The plural white and black keys 11w, 11b include drive units 11w1, 11b1 that drive the hammers 16w, 16b. The pivot centers of the hammers are located on the same straight line extending in the lateral direction. The drive unit 11b1 is located anterior to the drive unit 11w1. An upper-limit stopper 21 and a lower-limit stopper 20, which restrict the rocking movement of the hammers 16w, 16b, are provided to extend in the lateral direction.