An image forming apparatus, includes: a mainframe; a developing unit including a developing agent container that contains a developing agent and a developing agent carrier that carries the developing agent; and an image carrying unit including an image carrier that carries a developing agent image formed by an electrostatic latent image being developed by the developing agent carried on the developing agent carrier. The developing unit is attachable to and detachable from the image carrying unit. The developing unit is loadable in and unloadable from the mainframe in a state where the developing unit is integrally attached to the image carrying unit.