PURPOSE:To save space and to reduce cost by providing a rotating sleeve on which carrier which attracts toner by a potential difference is placed and an electromagnet which scrapes and pulls down the toner and the carrier by magnetic force. CONSTITUTION:The parts of 1st and 2nd comb-shaped electromagnets 1 and 2 whose projecting parts for magnetic pole 1a and 1b are arranged to be opposed to the rotating sleeve 3 project to the outside of a container 4, and coils 5 and 6 for generating magnetic field are wound thereto. The coils 5 and 6 are respectively connected to switches 7 and 8, and act as the eletromagnet by periodically opening and closing switches 7 and 8. The magnet is arranged inside the sleeve 3 so as to attract the carrier to the surface of the sleeve 3, and negative voltage 1 is given to the sleeve 3 from a DC power source. Therefore, residual toner on a photosensitive drum 12 is attracted to the sleeve 3 side, and gradually laminated, but the layer consisting of the toner and the carrier is scraped by the magnetic force with the actions of the electromagnets 1 and 2.