A developing device has a housing, a developer carrying member, a regulating blade, and a magnetic member. The regulating blade forms a regulating portion regulating the thickness of toner carried on the developer carrying member. The magnetic member is arranged inside the developer carrying member and has a plurality of magnetic poles including a regulating pole arranged at a position where the developer carrying member and the regulating blade are close together. The regulating pole is movable to a first position facing the regulating portion and to a second position rotated to the upstream side from the first position in the rotation direction of the developer carrying member during image formation. The developing device is operable in the developer removing mode in which, when no image is formed, the regulating pole is moved from the first position to the second position and is then returned to the first position.