PURPOSE: To provide a small-sized dust collector which is simple in structure, inexpensive in terms of equipment and operation costs, maintenance free, and can recover fine dust by a single device.

CONSTITUTION: A guide cylinder 3 which is formed cylindrically and changes a supply dust-containing air current into a revolving current on the upstream side and more than one fixed slanted blade plate 4 are installed. Induction cylinders 6, 7, 9 by double cylinders which have different inside diameters and an inner wall end shorter than an outer wall end and lead pipes 10 arranged in their central parts are installed behind the cylinder 3. In the cylinders 6, 7, 9, outlets 14, 16, 18 in the tangential line direction are formed in the back of the inner wall end position. Dust with each level of given centrifugal force is fluidized along the inner walls of the cylinders 6, 7, 9 to be sucked from outlets 14, 16, 18 and the pipe 10 to a recovery duct 11 to be recovered. The recovered air current containing dust thickly is circulated to a dust collector through a cyclone.