PURPOSE: To prevent deterioration of the surface of a photosensitive body and electrostatically charging of a conductive brush by fitting a shaft of the brush into a cam groove having a shunting groove fixed to both end parts of the photosensitive body, and shunting the brush from the photosensitive body, when copying stops.

CONSTITUTION: A conductive brush 2 is supported so as to be oscillatable by the tip of an arm 4 of a supporting shaft 3, and its shaft 2c is fitted into a cam groove 5a having a shunting groove 5b fixed to both end parts of a photosensitive body 1. Accordingly, at the time of copying, the shaft 2c of the brush 2 is guided along the cam groove 5a, the brush 2 contacts with the photosensitive body 1 and charging is executed, but when copying stops, the shunting groove 5b coincides with a position of the brush 2, and the brush 2 is shunted from the photosensitive body. Therefore, it is prevented that both of them contact with each other for a long period of time, deterioration of the surface of the photosensitive body 1 and sagging of the brush are prevented, and also deterioration of charging characteristics is prevented.