A mouse according to the present invention, comprises: a casing; a button part disposed on the casing, for generating a click signal by being pressed; and a sensing part fixedly disposed on the casing in the vicinity of the button part in such a fashion as to be slantedly lower than the button part; an amplifying part built in the casing, for amplifying the clock signal generated from the sensing part, up to a predetermined level; a filtering part built in the casing, for regulating the signal amplified by the amplifying part, up to a predetermined level; and a switching part for outputting selectively and one from the signals applied thereto from the button part and the sensing part. Since the mouse operates in a touch-sensor fashion, clicking noise is avoided when in use.