A cover closer having a drive unit for electrically opening and closing a cover of a copying machine or the like is described. The cover closer can ease the burden of manipulation of the cover and minimize the constraints on designing the main body of the copying machine and the like. The cover closer is provided with a compact drive unit having a high reduction ratio by the use of planetary gears which reduce the input torque necessary for opening and closing the cover, so as to downsize an electric motor used in the drive unit. The drive unit can therefore be installed within the hinge structure of the cover closer.