An image forming apparatus to which a cartridge is mountable and which is operable to form images at different image formation speeds, wherein the cartridge includes a memory medium having a memory area for storing information relating to image forming conditions of process means corresponding to the image formation speeds, the image forming apparatus includes a control unit for setting the image forming conditions, wherein the control unit sets an image forming condition corresponding to the image formation speed on the basis of the image forming condition of the process means responding to the image formation speed.