A keyboard device includes plural white keys, plural black keys, and plural hammers respectively engaged with the plural white and black keys. Vertical length of a drive portion for a first key and a second key are set the same, the first and second keys both being white keys, or both being black keys. Longitudinal position of hammer support portion of a first hammer engaged with the first key and longitudinal position of a hammer support portion of a second hammer engaged with the second key are set the same. Vertical positions of hammer support portions of the first and second hammers are respectively set according to a distance from a front end of an operation portion of the first key and a key support portion and a distance from a front end of an operation portion of the second key and a key support portion.