PURPOSE: To ease maintenance and inspection of a device by providing a process kit which is provided with a part or all of an image preserving body and an image forming means in one body, and is attached freely attachably and detachably to the main body of a device, and an exchanging member fitted to the process kit.

CONSTITUTION: In an image forming device, a process kit 14 is constituted of a photosensitive drum 3, an electric charging device 4, a developing device 5, a cleaning device 13 having a blade cleaner 13a and a toner storing well 13b and a cleaning device for a fixing device 16, in one body. This process kit 14 is provided freely attachably and detachably to/from a main body, and when said kit is fitted to the main body, the projected parts 14a, 14b of the process kit 14 is arranged so as to be engaged and guided with a guide 15 at the main body side. By such a constitution, the members exchanging periodically including the articles of consumption are exchanged easily, and maintenance and preservation for an image forming device are performed easily.