To provide a compact and versatile keyboard applicable for various note type inputs and capable of efficiently releasing heat generated from a main CPU mounted on a circuit board internally provided in a note type personal computer.

A fan cover 27 which is fastened and fixed to the lower face of a heat diffusion plate 4 via screws 26 between the lower face at the side end (right end, illustrated) of a supporting plate 3 and the side end (right end, illustrated) of the heat diffusion plate 4 is used to mount a heat release fan 25 on the side ends of the supporting plate 3 and the heat diffusion plate 4 for operating the heat release fan 25. In this way, air existing in a space 22 between the supporting plate 3 and the heat diffusion plate 4 is exhausted to the outside of a keyboard 1 to directly cool the heat diffusion plate 4, so that heat generated from a main CPU 29 mounted on a mother board 28 and transmitted to the heat diffusion plate 4 is efficiently released.