PURPOSE: To obtain an air cleaner not using a vinyl sheeting which would contribute to growth of microorganism such as mold, by providing nozzle parts for obtaining air curtain airflows between the outer periphery of a support frame and an inner periphery of a main body casing.

CONSTITUTION: With a blower 15 operated, the outside air is sucked in through an air suction port 18, is cleaned while flowing through a high-performance air filter 17, and is blown off from a clean air blow-off opening part 16, as indicated by arrows C. A portion of the air sucked in is caused to flow outward by the flow resistance in the filter 17, and flows through nozzle parts 21 provided between the outer periphery 19 of a support frame 17a and the inner periphery 20 of a main body casing 14. As a result, air curtain airflows are generated as indicated by arrows A, B to separate a clean air region D below the opening part 16 from an unclean air region E. Accordingly, it is unnecessary to use a vinyl sheeting or the like, passage of persons or articles into or out of the region D can be easily achieved without troubles such as a trouble to tuck up a curtain, smoothness of operations is enhanced, and an advantage on a hygienic basis is obtained.