A shaft seal for a rotating shaft includes a counter ring having an axial end surface of essentially annular shape which extends essentially perpendicular to the axis of rotation and a sliding ring which is resiliently forced against the counter ring end surface. The counter ring end surface has an axial recess which is positioned in that portion of the counter ring end surface which is closer to the axis. Crystalline contaminants are removed from the mutually contacting surfaces of the sliding and counter rings which results in a longer service period and improved operating characteristics of the shaft seal.
