A paper discharger is configured so as to perform paper conveying process to a first stacking tray and paper conveying process to a second stacking tray by a driving force from a single motor capable of reversible rotation in both directions. An image forming apparatus includes a movable door configured so as to support the second stacking tray, and a second gear train. Between a group of gears configuring the second gear train and a discharge roller is disposed a one way clutch configured so as to transmit driving force to the discharge roller only in the direction of discharging paper to the second stacking tray.