A keyboard device for an electronic musical Instrument, the keyboard device comprising: plural keys 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 the plural keys include plural white keys and plural black keys, wherein a pitch is assigned to each of the plural keys, from a low-pitched side to a high-pitched side and a length, in a longitudinal direction of each key, from the front end to the key support portion (13b, 13w) is different among the plural keys; plural hammers, each of which includes an engagement portion (Pb1, Pbw1) engaged with each of the plural keys, and each of which is supported by a hammer support portion (Hb, Hw) in order to rock with the rocking movement of each of the plural keys, wherein positions of the hammer support portions (Hb, Hw) in the vertical direction and in the longitudinal direction are the same, and the positions of the engagement portions (Pb1, Pbw1) in the vertical direction and in the longitudinal direction in the key release state are the same; and a first restricting member and a second restricting member that are arranged to extend in a direction of the arrangement of the plural keys, and that restrict the rocking movement of the plural hammers in order that the range of the rocking angle becomes the same for all of the plural hammers, wherein each of the plural hammers includes a mass member (16b3, 16w3) that becomes, for white keys and black keys respectively, lighter from a low-pitched side toward a high-pitched side of the keyboard device, and a key touch feeling of white and black keys becomes gradually lighter from the low-pitched side toward the high-pitched side, characterized in that, for white keys and black keys respectively, the distance from the key support portion (13b, 13w) to the engagement portion (Pb1, Pbw1) becomes gradually shorter from the low-pitched side toward the high-pitched side. plural keys 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 the plural keys include plural white keys and plural black keys, wherein a pitch is assigned to each of the plural keys, from a low-pitched side to a high-pitched side and a length, in a longitudinal direction of each key, from the front end to the key support portion (13b, 13w) is different among the plural keys; plural hammers, each of which includes an engagement portion (Pb1, Pbw1) engaged with each of the plural keys, and each of which is supported by a hammer support portion (Hb, Hw) in order to rock with the rocking movement of each of the plural keys, wherein positions of the hammer support portions (Hb, Hw) in the vertical direction and in the longitudinal direction are the same, and the positions of the engagement portions (Pb1, Pbw1) in the vertical direction and in the longitudinal direction in the key release state are the same; and a first restricting member and a second restricting member that are arranged to extend in a direction of the arrangement of the plural keys, and that restrict the rocking movement of the plural hammers in order that the range of the rocking angle becomes the same for all of the plural hammers, wherein each of the plural hammers includes a mass member (16b3, 16w3) that becomes, for white keys and black keys respectively, lighter from a low-pitched side toward a high-pitched side of the keyboard device, and a key touch feeling of white and black keys becomes gradually lighter from the low-pitched side toward the high-pitched side, characterized in that, for white keys and black keys respectively, the distance from the key support portion (13b, 13w) to the engagement portion (Pb1, Pbw1) becomes gradually shorter from the low-pitched side toward the high-pitched side.