An image forming apparatus of the present invention includes a pair of support plates supporting the rotary shaft of a photoconductive drum at axially opposite ends of the drum. One of the support plates is openable away from the body of the apparatus and loaded with a contact forming member including a current feed path for feeding a current from a high-tension power supply for charging to a charge roller, a wiring forming a current return path that allows a current to flow from the photoconductive drum to the ground of the power supply, and a plurality of contacts where the wiring and drum contact each other. A current flowing through the current return path is sensed to execute feedback control to the output of the high-tension power supply.