A charging device includes: a discharging electrode; a casing surrounding the discharging electrode and being provided with an opening in a member-to-be-charged side; a grid electrode provided in the opening and provided with a mesh portion having a plurality of through holes; a cleaning brush, including a base material and a plurality of fibers held on the base material, for cleaning the grid electrode by entrance of a part of the fibers into the through holes while contacting a surface of the grid electrode in the discharging electrode side; a shutter capable of shielding between the member-to-be-charged and the grid electrode; and a moving mechanism for moving the cleaning brush and the shutter along a longitudinal direction of the grid electrode. When the shutter is moved in a closing direction, the cleaning brush moves in advance of a leading end portion of the shutter with respect to the closing direction by a predetermined interval or more.