PURPOSE: To lengthen the life of a developing apparatus and hold an excellent image for a long period by performing the prevention of toner fixing to a blade for thinning a toner layer.

CONSTITUTION: When the number of copies counted by a copy counter reaches an assigned number, an input signal is sent to a CPU. As an output port, a drive motor for a developing roller 15+ a photoreceptor body is set to off at first, and then a lift 19 for cleaning a blade 17, for thinning a toner layer, is set to on. When the down movement of the lift 19 starts, the blade 17 for thinning the toner layer can be alienated, as an alienation path is controlled by an alienation path guide member 22 attached thereto, so as not to scratch the developing roller 15. During the alienation movement the toner fixed to the surface thereof is scraped off by a cleaning member 18.