The click mechanism comprises a spring made of a plate material and disposed on a rotatable plate that rotates integrally with a rotationally-manipulated shaft of an electric part; two cylindrical click pieces disposed on an outer perimeter of the rotatable plate in positions forming an angle of 180° with respect to each other so as to retractably protrude from the positions at different heights on the outer perimeter in an axial direction; and projections and depressions formed on an inner perimeter of a housing in a circumferential direction, in two upper and lower tiers in the axial direction. The projections and depressions in the two upper and lower tiers are staggered and the two click pieces are biased by the spring to be in resilient contact with the projections and depressions.