Abstract: An air purifier including a housing, a front cover, a front wire gauze filter, an anion generating pin board, a dust collector, and an active carbon filter, wherein: the housing has a plurality of parallel tracks horizontally disposed at different elevations for mounting the front wire gauze filter, the anion generating pin board, the dust collector, and the active carbon filter, a plurality of arched metal springs fixedly fastened to the parallel tracks for connecting power supply to the anion generating pin board and the dust collector, a side cover, and a micro switch which turns on power supply when the side cover is installed, or to turn off power supply when the side cover is removed from the housing; the dust collector has a plurality of equally spaced round holes over the whole area thereof, and is controlled to produce positive ions; the anion generating pin board has a plurality of triangular projecting plates perpendicularly raised from one side thereof and respectively aimed at the center of every