To prevent the unloading failure of a cartridge of a gripping mechanism by recognizing a distance between the gripping mechanism and the cartridge.

Communication is carried out between a sensor 6 attached to a gripping mechanism 5 and a semiconductor chip 2 attached to a cartridge 1 so that the sensor 6 receives unique information recorded in the semiconductor chip 2 to measure intensity of an electromagnetic wave. A distance between the cartridge 1 and the gripping mechanism 5 is recognized from the received intensity of the electromagnetic wave to recognize the position of the cartridge 1.