Abstract: A cyclone dust separator for the separation of coarse, small and very fine particles of dust from a dust-laden current of exhaust air or exhaust gas, which is conveyed eccentrically from above, and via a dust pipe, from a fan to a separating vessel is provided. The separated particles of dust are intercepted in a collector mounted underneath the separating vessel, a pipe conduit being inserted centrally from above into the separating vessel in order to lead off the current of pure air or pure gas, while a round upper part, in which the dust pipe terminates eccentrically, is mounted on the separating vessel. In the upper part the mixture of dust and air is subdivided into two separate currents taking an approximately circular coarse. This enables coarse, fine and very fine dust to be separated in an optimum manner even when considerable quantities of dust-laden air have to pass through the apparatus.