PURPOSE: To prolong the life of a developer and to obtain a developed picture of high quality by removing the developer from the surface of a developing roller after development by a developer removing roller equipped with magnets.

CONSTITUTION: The developer removing roller 13 is constituted by providing plural magnets 14 on the circumferential surface or by magnetizing the circumferential surface of a roller of a roller of ferromagnetic material to form plural magnetic poles. The developer on the developing roller 2 is removed therefrom after development by the developer removing roller 13 which rotates counterclockwise at a high speed in contact with the roller 2 and discharged into a hopper 8 for disposal. This developer is temporarily adsorbed on the surface of the removing roller 13, but separated by the centrifugal force of the removing roller 13 which rotates in a high speed and almost all of the developer is thrown into the hopper 8 by its inertial force. Thus, the life of the developer is prolonged and the developed picture of high quality is obtained.