IMAGE FORMING APPARATUS AND PROCESS CARTRIDGE

PROBLEM TO BE SOLVED: To provide an image forming apparatus having a developer carrier and an image carrier brought into contact with each other in a twisted relationship, and capable of good image formation.SOLUTION: In an image forming apparatus having a developer carrier 42 and an image carrier 1 brought into pressure contact with each other so that the respective central shafts are in a twisted relationship, a magnet roller 41 includes a magnetic pole that is the closest to a developing nip part, and a position of which in a circumferential direction of the developer carrier 42 changes in a longitudinal direction so that an area on a peripheral surface of the developer carrier 42 caused to have the highest magnetic flux density by the magnetic pole is located along the developing nip part in the longitudinal direction of the developer carrier 42.