For an oil seal (1) having a seal lip (6) with a slope (7) at the side of sealed fluid and a slope (8) at the side opposite to the sealed fluid, and a screw section (9) provided on the slope (8) for pushing back sealed fluid by a pumping effect at a time of rotation, in order to achieve low torque characteristics based on fluid lubrication by increasing the thickness of an oil film on sliding surfaces, an intermediate surface (10) is provided between the slopes (7, 8), and an oppositely threaded screw section (11) for sucking the sealed fluid by a pumping effect is provided on the intermediate surface (10) without reaching the boundary (13) between the intermediate surface (10) and the slope (8), so that a threadless region is provided in the entire circumference between the screw section (11) and the boundary (13).