A charging device includes a discharge electrode that charges a surface of a rotatable image carrier and extends along the image carrier, a case that extends along and encloses the discharge electrode with a side thereof nearest to the image carrier being open, a grid electrode provided between the image carrier and the discharge electrode, a cleaning member that cleans at least one of the discharge electrode, the case, and the grid electrode by moving along the case, a regulating portion that is provided between the cleaning member and the case and regulates a distance between the cleaning member and the case in a direction orthogonal to the direction of movement of the cleaning member by coming into contact with the cleaning member or the case, and a supporting portion that supports the regulating portion and allows the regulating portion to move away from the cleaning member or the case.