To provide a toner cartridge inventory control system by which burdens of inventory control of toner cartridges and accompanied works are reduced and cost such as the carriage can be suppressed.

The toner cartridge inventory control system is performed by a network such as an inter-net 303. Information of an nonvolatile memory built in a mounted toner cartridge is read in by means of an LBP 100 and information indicating that an unused toner cartridge is mounted or remaining amount of a toner is at a definite amount or less is transmitted to a control server 601. The control server 601 receiving this information reads data base and automatically performs the inventory control, a purchase instruction or an ordering of the toner cartridge and in addition, performs this ordering and shipping by making a number suitable to the inventory condition of a user in the lump.