A method of manufacturing an image drum includes fixing a control circuit board inside the drum body so that a plurality of terminals of the control circuit board are located in the slot formed longitudinally on the drum body, forming an insulation layer to the entire external surface of the drum body, forming connection parts by removing parts of the insulation layer where the terminals of the control circuit board are formed, forming electrode forming grooves including the insulation layer as a base on the external surface of the drum body comprising the connection parts thereon, and forming a plurality of ring electrodes to be connected to respective terminals among the plurality of the terminals, respectively, through the connection parts.