<p>A charging device in an image forming apparatus is provided with an image carrier such as a photosensitive drum or image forming medium on which an electrostatic laten image is developed. The charging device has a brush roller for charging the carrier. The roller brush is rotatably mounted and formed with inclined fibers planted on a shaft, the roller brush satisfying the following formulas: <MATH> <MATH> wherein L represents a length of fibers and L represents a thickness of the brush. The charging device further has means for removing the charges from the surface of the brush roller and means for cleaning an area where the charges are removed by the charge removing means. <IMAGE></p>
