An annular filter element and sealing element for an oil separator of a crankcase ventilation system, the filter element has a covering surface extending parallel to a direction of flow, together with at least one cover element covering surface in at least some regions. An oil separator is taught having the filter element with at least one pressure control valve controlling crankcase pressure and has a valve closing body that operates in conjunction with a valve seat. The sealing element having at least one radially sealing region that is configured to act in the direction of the radius of the annular filter element, and at least one axially sealing region that is configured to act in the direction of the longitudinal axis of the annular filter element.