PURPOSE: To perform a good development by supplying a proper quantity of a developing agent to a material to be developed, by providing a removing material for the developing agent which is moving at the relative speed to a supplying material of the developing agent and remove the surplus developing material by being brought into contact with brush hairs and controlls the quantity of the developing agent to be supplied.

CONSTITUTION: Toner T which is delivered to a developing roller 4 is moved in accordance with the rotation of the roller 4 and a part of the surplus toner T is scraped by a recovery roller 6. The toner T contained floatingly in brush hairs 12 is shaked off by scraping action of the top end of the brush hairs 12 caused by slits 21... of the roller 6 and vibration of the brush hairs 12 at that time and it is flowed out to a recovery path 20 side through the slits 21... and is dropped on a carrying roller 7 and is transported to a bottom opening part 18 side of a toner hopper 5 in accordance with rotation. As the surplus toner T is recovered by the roller 6, the quantity of toner T on the roller 4 is regulated always in a constant uniform quantity, and a safe and good development is performed.