A low cost and high accuracy replacing part identification system capable of detecting and excluding the dishonest use of an image forming apparatus containing a consumable. A memory storage device having a particular ID number stored therein is attached to a toner cartridge. If the toner cartridge is used, hysteresis data (data that cannot be re-written to its original value) is stored in the memory storage device and the ID number is stored in an ID storing unit to prevent the cartridge from being able to be used by other apparatuses. Since a control unit detects the number of time of use and a toner level detecting unit detects the data of a toner level in the toner cartridge to store as the hysteresis data in the memory storage device, a toner cartridge which imitation toner was refilled can be detected and prevented from being used.