PURPOSE: To provide a color image forming device capable of efficiently working, being easily handled and saving a cost, even if the color image forming device is used as for a black-and-white image or a color image.

CONSTITUTION: In the color image forming device 10 having an image forming body, respective developing units for Y, M, C, and black 201-204 arranged around the image forming body and a cleaning part 116, the device 10 is constituted of a detachable process cartridge 2102 composed of the image forming body, the black developing unit 204 and the cleaning part 116 and a detachable unit composed of the developing units for Y, M, C 201-203 and simultaneously, attaching/detaching directions is parallel with the rotary shaft of the image forming body in the process cartridge 2102 and is perpendicular to be rotary shaft in the unit. Arrangement that the unit interferes at the time of attaching/ detaching the process cartridge 2102 is adopted, the unit takes priority at the time of attaching/detaching and the process cartridge 2102 and the unit are attached/detached in directions orthogonally crossed or parallel with each other.