PURPOSE: To provide an electrophotographic image forming device using an image carrying belt, capable of making the image carrying belt press-contact to and separate from a cleaning member without reducing feeding force in the midst of forming the image, and efficiently forming a faultless image.

CONSTITUTION: This device is provided with belt driving devices 15 and 21 for feeding the image carrying belt 20 forming and carrying a toner image on its surface at fixed speed, and a cleaning device 25 having the cleaning member 26 capable of press-contacting to and separating from the belt 20; and it is equipped with belt feeding force increasing devices 16 and 24 increasing the feeding force of the belt 20 when the member 26 press-contacts to the belt 20, or a belt feeding force decreasing device decreasing the feeding force of the belt 20 when the member 26 separates from the belt 20.