A centrifugal separator for cleaning of a gas containing liquid impurities, wherein the centrifugal separator comprises - a stationary casing, which encloses a separation space and has an inner wall surface facing the separation space, wherein the separation space permits the gas to flow therethrough, - an inlet for the gas to be cleaned, - a rotating member, which is provided in the separation space downstream the inlet with respect to the gas flow and arranged to rotate in a direction (r) of rotation around an axis (x) of rotation, wherein the rotating member is adapted to bring the gas to rotation in the directions (r) of rotation for separation, by means of centrifugal forces, of at least a part of the liquid impurities from the gas, - a gas outlet, which with respect to the gas flow is provided downstream the rotating member for discharge of the cleaned gas, - at least a first liquid outlet for discharge of the liquid impurities, wherein the first liquid outlet comprises at least one outlet hole extending through the inner wall surface, and - an annular surface, which extends inwardly from the inner wall surface and is located downstream the outlet hole, wherein the first liquid outlet comprises an annular shield element, which extends from the annular surface at a distance from the outlet hole, and wherein the annular shield element and the annular surface form an annular groove, characterized in that the shield element and the groove are located radially inside the outlet hole, that the groove has on open annular upstream end and a closed annular downstream end, that the upstream end is located axially upstream the downstream end of the outlet hole and also axially upstream the upstream end of the outlet hole, and that the liquid impurities flowing along the inner wall surface will be caught by means of the groove. - a stationary casing, which encloses a separation space and has an inner wall surface facing the separation space, wherein the separation space permits the gas to flow therethrough, - an inlet for the gas to be cleaned, - a rotating member, which is provided in the separation space downstream the inlet with respect to the gas flow and arranged to rotate in a direction (r) of rotation around an axis (x) of rotation, wherein the rotating member is adapted to bring the gas to rotation in the directions (r) of rotation for separation, by means of centrifugal forces, of at least a part of the liquid impurities from the gas, - a gas outlet, which with respect to the gas flow is provided downstream the rotating member for discharge of the cleaned gas, - at least a first liquid outlet for discharge of the liquid impurities, wherein the first liquid outlet comprises at least one outlet hole extending through the inner wall surface, and - an annular surface, which extends inwardly from the inner wall surface and is located downstream the outlet hole, wherein the first liquid outlet comprises an annular shield element, which extends from the annular surface at a distance from the outlet hole, and wherein the annular shield element and the annular surface form an annular groove, characterized in that the shield element and the groove are located radially inside the outlet hole, that the groove has on open annular upstream end and a closed annular downstream end, that the upstream end is located axially upstream the downstream end of the outlet hole and also axially upstream the upstream end of the outlet hole, and that the liquid impurities flowing along the inner wall surface will be caught by means of the groove.