PURPOSE: To improve agitating efficiency and to prolong the life of a developer by providing an agitator in a trough disposed in the rear end of a scraper.

CONSTITUTION: The developer in an upper trough 20a falls successively according to the revolutions of screws 37a, 37b, or is gathered in the central part where the developer overflows and falls completely from the trough 20a. A lower trough 23c formed of a developer vessel is located below the trough 20a of the scraper 20 and said trough 23c is connected to the inclined bottom plate of a developing vessel 23. The developer dropped from the trough 20a of the scraper 20 is received in the trough 23c, where the developer accumulates. Since a lower agitator 38 which rotates counterclockwise is provided in said trough 23c, the developer accumulating in the trough 23c is again agitated.