PURPOSE: To form a stable developer thin layer on a sleeve with not only a magnetic toner but also a nonmagnetic toner by inclining and arranging an elastic body regulating member, which regulates application of a developer, so that the downstream side in the moving direction of a developer carrier is made wider.

CONSTITUTION: An elastic body blade 3 consists of rubber, plastics, or the like having a proper elastic modulus, and this blade 3 is inclined to the downstream side in the rotation direction of a sleeve 2 and is brought into contact with the sleeve 2 with a proper contacting pressure. A toner having a large sticking force due to electrostatic attraction and affinity pushes aside the blade 3 because of elasticity of the blade 3 and passes the contacting part between the sleeve 2 and the blade 3 in accordance with rotation of the sleeve 2, but a toner having a weak sticking force is scraped by the blade 3, and it is scraped repeatedly until the sticking force is increased, and only the toner acquiring a prescribed quantity of electrostatic charge is coated on the thin layer.