To solve a problem that a tray is excessively elevated/lowered to break a peripheral device if a sensor for detecting the elevating/lowering position of the tray is failed.

A sheet stacking device has a spring for regulating an elevating/lowering range of a tray. When the tray exceeds the elevating/lowering range, the spring is compressed to load a driving unit 610 driving the tray. The load on the driving unit 610 is determined by a change of the driving current of the driving unit 610 detected by an overload detection unit 620 by a drive control unit 630. When it is determined that the driving unit 610 is in a loaded condition, the driving current is blocked to stop the elevating/lowering of the tray.