A sealing device is provided which is capable of exhibiting a sealing function even in a state where fluid pressure is low or in a state where there is no fluid pressure, while suppressing sliding torque to a low level.
The sealing device is characterized by including: an outer peripheral ring 2000 made of resin that is in intimate contact with a side wall surface of an annular groove 4100 at a low pressure side (L) thereof, and slides with respect to an inner peripheral surface of a shaft hole in a housing 5000 through which a shaft 4000 is inserted; and an inner peripheral ring 3000 made of a rubber-like elastic body that is in intimate contact with an inner peripheral surface of the outer peripheral ring 2000 and a groove bottom surface of the annular groove 4100, respectively, thereby to push the outer peripheral ring 2000 toward an outer peripheral surface side thereof; wherein the outer peripheral ring 2000 is formed on its outer peripheral surface with a concave portion 2220 which extends from an end of a high pressure side (H) to a position which does not arrive at an end of a low pressure side, so as to introduce fluid thereinto from the high pressure side.