An image forming apparatus includes a developing device, a supply tube, a feeding screw and a magnetic member. The developing device develops an electrostatic image formed on an image bearing member with a magnetic developer. The supply tube supplies the magnetic developer into the developing device. The feeding screw feeds the magnetic developer in the supply tube. The magnetic member confines the magnetic developer in a clearance between the supply tube and the feeding screw. The magnetic member is provided at a substantially radially outermost portion of the feeding screw.