Abstract: A cyclone type dust collector having a raw air intake aperture, an air separating chamber including a cylinder of upper part and a reversed circular cone of lower part, inner and outer clean air exhaust ducts, the bottom of the air exhaust ducts being closed, the bottom of the reversed circular cone being opened, the exhaust ducts coaxially disposed passing through the air separating chamber, and the surface of the exhaust ducts being provided with many small holes or mesh, small balls or the like being filled between the outer and inner clean air exhaust ducts.