To make image forming cartridges common in terms of respective colors.

In the electrophotographic printer, a plurality of image forming cartridges are attached in a state where they are arranged in a line, and also display parts for color discrimination are provided at the respective attaching positions. Then, a display part for discrimination corresponding to the color of toner supplied from a separate toner cartridge is provided in each of the plurality of image forming cartridges so that it can be set. The display part for discrimination provided in each of the image forming cartridges is constituted of a seal stuck to a groove part formed on the image forming cartridge.