In a switch device, a switch part is turned ON/OFF by operation of an operating knob housed in a recessed part of a panel so that a movable terminal and a fixed terminal are in contact or are separated. An outside face, opposing an inner peripheral face of the recessed part of the panel, of the operating knob is an inclined face that is inclined inward of the operating knob in going downward. A gap that widens in going downward is formed between the outside face of the operating knob and the inner peripheral face of the recessed part of the panel. Accordingly, the device can ensure stable operation of the operating knob by discharging, from the gap between the panel and the operating knob, liquid that has entered the gap, and that can improve the appearance.