PURPOSE: To unnecessitate the periodic shake down of dust and to unnecessitate the high-pressure impression by rotating the dust collecting plates consisting of a dielectric material, abutting and sliding the brushes thereon.

CONSTITUTION: In relation to a dust collector in an air purifier performing the purification of the polluted air, a shaft 3 is perforated through the central parts of the discoid dust collecting plates 2 formed with a dielectric material in the inside of an outer shell 1 and made freely rotatable and the brushes 8 are fixed to the outer shell 1 so that these are press-contacted between the dust collecting plates 2 by means of nearly U-shaped springs 9. In such a way, since the dust collection is performed by using the static electricity generated by the friction of the dielectric material, the impression of the high voltage is unnecessitated and the rescattering of dust is prevented with the self-cleaning effect.