A keyboard device for an electronic musical instrument, the keyboard device comprising: plural white keys and black keys 11b) that are supported by a key support portion (13b, 13w) in order that front ends thereof rock in the vertical direction by a key depression/release operation by a performer, wherein a pitch is assigned to each of the plural white keys and black keys; plural white-key hammers, each of which includes an engagement portion (Pw) engaged with a respective one of the plural white keys, and each of which is supported by a hammer support portion (Hw) in order to rock with the rocking movement of the respective one of the plural white keys, plural black-key hammers, each of which includes an engagement portion (Pb) engaged with a respective one of the plural black keys, and each of which is supported by a hammer support portion (Hb) in order to rock with the rocking movement of the respective one of the plural black keys, characterized in that a length, in a longitudinal direction of each key, from the front end to the key support portion is different among the plural white keys and among the plural black keys, respectively, positions of the hammer support portions (Hw, Hb) in the vertical direction and in the longitudinal direction are the same for the plural white-key hammers and black-key hammers, the positions of the engagement portions (Pw,) in the vertical direction and in the longitudinal direction in the key release state are the same for the plural white-key hammers, the positions of the engagement portions (Pb) in the vertical direction and in the longitudinal direction in the key release state are the same for the plural black-key hammers, and the engagement portions of the plural black-key hammers are located anterior in the longitudinal direction with relation to the front end of the keys, to the engagement portions of the plural white-key hammers; and a first restricting member and a second restricting member that are arranged to extend in the direction of the arrangement of the plural white keys and black keys, and that restrict the rocking movement of the plural white-key hammers and black-key hammers in order that the range of the rocking angle becomes the same for all of the plural white-key hammers and black-key hammers. plural white keys and black keys 11b) that are supported by a key support portion (13b, 13w) in order that front ends thereof rock in the vertical direction by a key depression/release operation by a performer, wherein a pitch is assigned to each of the plural white keys and black keys; plural white-key hammers, each of which includes an engagement portion (Pw) engaged with a respective one of the plural white keys, and each of which is supported by a hammer support portion (Hw) in order to rock with the rocking movement of the respective one of the plural white keys, plural black-key hammers, each of which includes an engagement portion (Pb) engaged with a respective one of the plural black keys, and each of which is supported by a hammer support portion (Hb) in order to rock with the rocking movement of the respective one of the plural black keys, characterized in that a length, in a longitudinal direction of each key, from the front end to the key support portion is different among the plural white keys and among the plural black keys, respectively, positions of the hammer support portions (Hw, Hb) in the vertical direction and in the longitudinal direction are the same for the plural white-key hammers and black-key hammers, the positions of the engagement portions (Pw,) in the vertical direction and in the longitudinal direction in the key release state are the same for the plural white-key hammers, the positions of the engagement portions (Pb) in the vertical direction and in the longitudinal direction in the key release state are the same for the plural black-key hammers, and the engagement portions of the plural black-key hammers are located anterior in the longitudinal direction with relation to the front end of the keys, to the engagement portions of the plural white-key hammers; and a first restricting member and a second restricting member that are arranged to extend in the direction of the arrangement of the plural white keys and black keys, and that restrict the rocking movement of the plural white-key hammers and black-key hammers in order that the range of the rocking angle becomes the same for all of the plural white-key hammers and black-key hammers.