The copying apparatus of the present invention comprises an exposure station for exposing an original to light; automatic document feeder for positioning the first surface of the original and turning the original upside down after an exposure; a photosensitive drum; a charger for sensitizing the photosensitive drum; an optical system for projecting the image of the original onto the sensitized photosensitive drum, an erasing unit for irradiating the sensitized photosensitive member with an erasing light and a controller for controlling the erasing unit to erase the images corresponding to binding margins of the first and second surfaces of the original.