A needle electrode and a cleaning member are provided. A plurality of needles are arrayed upon the needle electrode in a straight line, and protrude towards a surface of a photoreceptor. The cleaning member is disposed movably along the array direction of the plurality of needles between the surface of the photoreceptor and the needle electrode. When the cleaning member moves, the tip portion of each of the plurality of needles in the arranged order, after having been embedded from the surface of the cleaning member into its interior, then exits to the exterior of the cleaning member.