PURPOSE: To reduce the staying and heaping of a developer through the use of an air flow occurring in the vicinity of a doctor blade by adopting a constitution that plural air holes are pierced on the doctor blade whose edge is turned to a toner recovering magnetic roll along a longitudinal direction.

CONSTITUTION: Doctor blades 17 and 8 whose edges are turned to respective roll faces between a magnetic roll 4 disposed opposite to a photosensitive drum 5 and the toner recovering magnetic roll 6, attached and disposed to a supporting beam 9. On the other hand, plural air holes 17a are pierced on the doctor blade 17 turned to the toner recovering magnetic roll 6 along the longitudinal direction at an equal interval. Thus, the air holes 17a are formed on the doctor blade 17, so that the air flow generated by the rotation of the photosensitive drum 5 passes through the air holes 17a, and flows out in the direction of the arrow. Thus, the developer heaped on the doctor blades 17 and 8 and the back surface of the supporting beam 9 can be reduced.