A conveyor includes: a conveyor roller unit including a conveyor roller; a transmission mechanism; a driven roller unit including a driven roller; a supporting member which supports the conveyor roller unit and the driven roller unit to allow the conveyor roller unit and the driven roller unit to take a conveyance position or a retracted position; and a movable member which is movable between a first position where the conveyor roller and the driven roller take the conveyance position and a second position where the conveyor roller and the driven roller take the refracted position. The movable member moves from the second position to the first position when the conveyor roller in the second position rotates in one direction.