The invention provides a sealing device which can inhibit an external dust in an atmospheric side from intruding into a lip end, thereby inhibiting a sealing fluid leakage by trapped dust. In a sealing device inhibiting leakage of a sealing fluid in an inboard side to an atmospheric side, coming into contact with a shaft by a seal lip end and circumferentially having in an atmospheric side inclined surface of the seal lip with a plurality of screws exerting a pumping action to the sealing fluid, a three-dimensional shape for preventing the dust intrusion is provided between the screws so as to inhibit the external dust intrusion in the atmospheric side toward the lip end. The three-dimensional shape is constructed by a projection or a groove extending in a parallel direction to the lip end. The projection or the groove is connected to the screws longitudinally in both end portions.