PURPOSE: To obtain high collection efficiency in a maintenance free state, by adhering an ion to the surface of a collector being a dielectric body to charge the same and after adhering dust particles to the charged surface, destaticizing the surface of the dielectric body not only to remove the dust particles but also to regenerate the dielectric body.

CONSTITUTION: The dust particles 13 in dirty air 1 are charged in desired quantity by a corona discharge power source 2. The dielectric film 4 mounted to the main surface of a cylindrical rotary drum 3 becoming a rotary body in the circumferential direction thereof is charged from the first potential to the second potential by a polarizing power source 5 becoming a charging means and adheres and collects the dust particles 13 guided to the vicinity of said film 4 of Columns force. A regenerating power source 11 becoming a destaticizing means releases the charge of the dust particles 13 to substantially destaticize, for example, the first potential and the dust particles 13 are released from the dielectric film 14 by a regenerating blade 6. By this operation, purified air 10 is obtained.