An image forming apparatus including a primary transfer unit to transfer toner images of plural colors on image carriers onto an intermediate transfer member; a secondary transfer unit to transfer the toner images onto a transfer material; and a pre-secondary transfer discharge unit to discharge charges of the toner images, wherein the discharge unit includes a scorotron having a grid electrode and a discharging electrode; an opposing electrode opposed to the grid electrode through the intermediate transfer member; a first voltage unit to apply a reverse polarity voltage of the toner images to the discharging electrode; a second voltage applying unit to apply a same polarity voltage of the toner images to the grid electrode; a cleaning unit of the grid electrode; a current detecting unit; and a controller to control a timing to clean the grid electrode according to the detected current.