A wiring duct plug that does not have a movable part for selecting any of a plurality of conductive lines, and has a high operational reliability is provided. A wiring duct plug can be directly connected to a respectively corresponding conductive line, and comprises a plurality of movable electrode terminals, rotating together with a rotator. At the connection position, at least two but not all of the plurality of movable electrode terminals are joined into one at the base end portion and electrically coupled to one of non-movable electrode terminals, and the remaining movable electrode terminal is electrically coupled to the other non-movable electrode terminal.