A switch device includes a busbar, a switch knob, a movable contact sliding part in the busbar, a movable contact configured to slide while elastically contacting the movable contact sliding part, root parts in the movable contact sliding part, and a fixed contact. The root parts are engaged with the movable contact. An engaging position of the movable contact is shifted from the one of the root parts to another one so as to switch connecting relation. A groove part and a rib are formed in the busbar between the one of the root parts and another one of the root parts. The rib is configured to abut against the movable contact to deform the movable contact in an opposite direction to a direction where the movable contact is engaged with the root parts, in a state where the movable contact is positioned at the groove part.