A multi cyclone dust separating apparatus including a first cyclone and a second cyclone having a plurality of cyclones formed on an outer side of the first cyclone. The first cyclone includes a first cyclone chamber centrifugally separating dust from air, a chamber outer wall, a first inlet and a first outlet forming the first cyclone chamber. The second cyclone unit includes a plurality of cyclones arranged along an outer circumference of the first chamber outer wall, and having a second cyclone chamber centrifugally separating minute dusts from air drawn in from the first cyclone unit, a second chamber outer wall forming the second cyclone chamber, second inlet, and a second outlet. The second inlet of each second cyclone of the second cyclone unit is lower than the first inlet of the first cyclone unit and freely settable. |