AIR CLEANER

PURPOSE:To improve the dust collecting efficiency and to prolong the life of filter by disposing electret filters accompanied with metallic nets in wave form, and dielectrically polarizing the electret filters having lost the dielectric force by collecting charged particle. CONSTITUTION:The discharge part 1 provided in the upstream side of air flow consists of high potential dischage lines 2, earthed metallic electrode plates 3, and high potential electric power source 4. In the dust collecting part 5 provided in the downstream side of air flow, the electret filters 6 are disposed in wave form and high potential discharge lines 7 and metallic nets 8 are provided respectively in upstream side and downstream side so that the filters are between them, and high potential is impressed to the high potential discharge lines 7 from an electric power source 9. Thus, by raising the effective area of electret filter to reduce the wind velocity passing through the filters, the pressure loss is reduced and the dust collecting efficiency is improved, and, by impressing high potential to the high potential discharge lines 7, the filters having lost the dielectric force are dielectrically polarized to collect charged particles again by the dielectric force.