Cyclone with upstream baffle

having a bag-free floor-treating appliance (1) with a centrifugal separator (2) having a separation chamber (5) having an air inlet (3), an air outlet (6) and an ejection window (16), wherein an air guide means in the separation space (8) with a baffle (9) is arranged for guiding air. The ejection window (16) in a wall (15) of the separation space (5) in the radially lateral direction open and the baffle (9) from the air inlet (3) as seen at least in part prior to ejection window (16) arranged or extends at least at the air inlet (3) facing the edge (17) of said ejection window (16) zoom. Such an arrangement increases the separation efficiency especially small particles at the same time remains constant volume flow and without any additional losses to the pressure difference in the centrifugal separator.