An image forming apparatus includes an image carrier, a developer carrier arranged to face the image carrier to form a developing nip portion, which carries developer containing toner for developing a latent image formed on the image carrier, a developing unit having a developer regulating member that regulates a thickness of a layer of the carried developer, an air sending duct having an air sending path provided on the developing unit, which sends air to the developer carrier and a suction duct having a suction path provided on the developing unit, which sucks air from the developer carrier. The developer regulating member is arranged on an air sending duct side, and the air sending and suction paths are arranged to be connected by forming a space surrounded by a surface of the developer carrier, the developer regulating member and a wall forming the suction path.