Toner cartridges 32C, 32M, 32Y, and 32K have storage elements 33C, 33M, 33Y, and 33K mounted thereon to transmit information carried on electromagnetic wave in a predetermined frequency band. An information receiver transmitter unit 30 is located in a neighborhood of an end of a developer unit 23 with the toner cartridges 32C, 32M, 32Y, and 32K attached thereto to transmit information carried on the electromagnetic wave in the predetermined frequency band to and from a color laser printer 20. While the developer unit 23 is rotated to develop each color component image with a supply of toner from the corresponding one of the toner cartridges 32C, 32M, 32Y, and 32K, the information receiver transmitter unit 30 is controlled to write a cumulative toner consumption and a cumulative number of printed sheets into the corresponding one of the storage elements 33C, 33M, 33Y, and 33K.