To obtain an image forming device provided with a developing device constituted so that failure such as density irregularity can be eliminated in the case that visible image processing is executed by using developer made into a thin layer on a developing sleeve.

This image forming device is constituted by being provided with the developing device used for the visible image processing of a latent image formed on a latent image carrier 2 by an electrophotographic copying system. The developing device is provided with a developing sleeve 5Y1 facing the carrier 2 and supplying the developer and a blade 5Y6 abutting on the sleeve 5Y1 and making the developer carried on the sleeve 5Y1 into the thin layer in a developing unit 5Y. Then, the sleeve 5Y1 is constituted so that the abutting position thereof on the blade 5Y6 is successively made different at a time other than an image forming time.