The air cleaner (32) comprises a base member (41) including a base wall (41A) extending substantially horizontally, and a cover member (42) attached to an upper side of the base wall to jointly define a filter chamber (70) for receiving a filter element (43) therein. The air cleaner further includes a passage member (44) communicating with the filter chamber and incorporated with a plurality of air ejection pipes (44C) each surrounded by an annular air inlet passage (44E) fitted with guide vanes (44D) for rotating the air flow, and a case member (45) defining separation chambers (45C) for separating dust from the rotating air flow. The passage member (44) is interposed between the cover member (42) and the case member (45).