PURPOSE: To improve operability by providing plural key switch supporting members so that the positions can be separately changed to the enclosure of a keyboard device.

CONSTITUTION: By loosing a knob 7, turning a reinforce chassis 5 in an arrow direction and changing the position, the positions of four key switches 4 in one line supported by the chassis 5 can be changed for each switch and arbitrarily controlled corresponding to the hand of a user. When the keys are fixed at the desired positions, the chassis 5 is fixed by fastening the knob 7 and the key positions are fixed. Thus, the operability of the keyboard device can be improved.