To provide a developing device, a process cartridge, and an image forming apparatus preventing occurrence of sleeve ghost by an inexpensive method and obtaining stable images for a long period of time.

The developing device is provided with a developer circulation regulation means 50 abutting against a developer carrier 42 at the part at the upstream side from a developer layer thickness regulation part of a developer layer thickness regulation means 45 with respect to the rotational direction of the developer carrier 42 and at the downstream side from the developing position A with respect to the rotational direction of the developer carrier 42, in which the abutting part against the developer carrier 42 is flexible. An area where an agitation conveyance means 44 is disposed and an area where the developer layer thickness regulation means 45 is disposed are partitioned by the circulation regulation means 50.