PURPOSE: To destaticize the entire area of an image forming body uniformly by setting the position relation between the discharge center of a secondary corona discharger and image exposure properly.

CONSTITUTION: Both end parts of a slit 4 for image exposure, that is, the parts corresponding to both end parts of an image forming body are displaced on the entrance side of the corona discharge region of an image forming body. Or a discharge line 2 is disposed diagonally with respect to the linear slit 4. The efficiency of destaticization in the central part is decreased and that in both end parts is increased by such formation. As a result, the efficiency of destaticization over the entire area of the image forming body is made approximately uniform. Thus the entire area of the image forming body is destaticized uniformly.