To provide the keyboard device of the electronic musical instrument which prevents noise from being generated by the abutting surfaces of a keyboard frame made of a steel plate and a keyboard reinforcing member made of a steel plate without causing an increase in the number of components or an increase in assembly man-hours.

The keyboard device of the electronic musical instrument is constituted by fitting the keyboard reinforcing member 3 made of the steel plate to the keyboard frame 2 made of the steel plate, providing the keyboard frame 2 with keys 1 so that they can freely swing up and down, and providing hammers 5 which rotate by receiving pressing forces when the keys 1 are pressed and return when the keys are released from being pressed below the keys 1; and resin 10 is molded integrally on the surface of the keyboard frame 2 which abuts against the keyboard reinforcing member 3 by outsert molding.