In an air cleaner (32), three cyclone dust collection units (34) are arranged on one side of a filter dust collection unit (35) in a mutually parallel relationship. The cyclone dust collection units are arranged along a circumferential direction of the filter dust collection unit, and the central cyclone dust collection unit has a smaller diameter than the remaining cyclone dust collection units positioned on either side of the central cyclone dust collection unit so that the dust collection units can be accommodated in a rectangular profile is a highly space efficient manner.