The article deals with the design and the experimentally verified description of the horizontal dust-collector with a rotating baffle. The device is characterized by its compact structure, high efficiency, and low pressure drop. The principle of operation of the apparatus is based on putting the dusted gas into swirling motion with a rotational velocity equal to rotational speed in the flow channel. The value of centrifugal force reacting on particles is, in this case, limited only by strength of material and power necessary to force the rotational velocity of the gas stream. The separated dust is collected by slots situated crosswise to the gas flow on the outer wall of the flow channel. Research was done on the apparatus with an inner diameter of 100 mm, outer diameter of 216 mm, and channel length of 298 mm, at a rotational velocity from 2000 to 3700 rpm for rate of flow from 300 to 660 m(3)/h.