A push & lock unit includes cam sections mounted on an outer wall of a rotary body that is disposed on an underside of an operating body, and each one of the cam sections contacts a saw-tooth section disposed on a lower end of a rib on an inner wall of a cover and a projection disposed at a bottom center of a housing in response to an up and down movement of the operating body, whereby the rotary body is rotated. When the operating body is pushed, a push face thereof is locked at a position almost flush with an outer face of a panel. When the operating body is pushed once more, it is released from the lock, and restores to a state where the operating body projects from the outer face of the panel.