PURPOSE: To prevent the re-scattering of accumulated dust by mounting a charging film to the outer periphery of a cylindrical conductor and arranging an exhaust pipe to the outer periphery of a rotary cylindrical body equipped with a means for applying voltage to the cylindrical conductor so as to provide a fine interval to provide a suction means to the exhaust pipe.

CONSTITUTION: A charging film 1 is charged by applying voltage to a rotary conductor 2 and dust charged in polarity reverse to that of the charging film 1 is attracted to the surface of the charging film 1. The rotary cylindrical body constituted of the rotary conductor 2 and the charging film 1 is rotated around a rotary shaft 7. Since negative pressure is applied to an exhaust pipe 5 by an exhaust apparatus such as a vacuum pump, the air in an atmospheric space passes through a fine gap 4 to be discharged from the exhaust pipe 5. Since the cross-sectional area of the flow passage of the fine gap is small, flow velocity becomes high and the dust attracted to the surface of the charging film 1 is released from the surface of the charging film 1 by the flow of air having high flow velocity to be discharged from the exhaust pipe 5 along with air.