After a first image is formed on an image bearing member, the potential of the image bearing member is attenuated, and then, the image bearing member is re-charged. Thereafter, a second image is formed. The image forming apparatus includes a potential sensor for detecting the surface potential of the image bearing member, and in accordance with the output of the potential sensor, amount of potential attenuation and/or amount of re-charging is controlled so that the potential difference between the potential of the first developed portion after the re-charging and the background potential is converged into a predetermined target range.