Provided is apparatus for controlling flow rate of gases used in semiconductor device by differential pressure by generating differential pressure in a fluid path. A reinforcement panel is configured to abut the door inner panel along the header portion and further defines the window opening. Each actuator has a footprint size smaller than that of the corresponding chamber, and is sized and arranged to provide individual support to the bones of the human foot. A control device controls the secondary transfer current applied to the secondary transfer member or the conductive member in accordance with the change in the primary transfer voltage in the sub-scanning direction detected by the power supply unit. The user specifies one recovery point out of the recovery point candidates, and requests to restore the user data volume.