One-way rotary switch

A one-way rotary switch with a first stopper face (7b) provided on each of click teeth (7) of a click teeth portion (8) of a click mechanism (14) affording a click feeling during the rotation-operation of a rotary knob (11). Second stopper face (13b) is provided on a tooth portion (13) of a click piece (10). The first stopper face (7b) and the second stopper face (13b) cooperate to prevent the rotary knob (11) from rotating in a direction opposite to a direction indicated by an arrow A. Consequently, there is no need for providing a stopper as an additional component.