A sealing device for sealing an annular gap between a shaft and a housing, comprising: a reinforcing ring having an inward flange portion; and a seal main body made of a rubber-like elastic body, provided integrally with the reinforcing ring, and having a main lip that extends from a vicinity of a tip of the inward flange portion to a sealed area side, and is adapted to slidably come into contact with an outer peripheral surface of the shaft, and a dust lip that extends from the vicinity of the tip of the inward flange portion to a side opposite to the sealed area, and is adapted to slidably come into contact with the outer peripheral surface of the shaft, wherein a bumper portion made of a rubber-like elastic body only and adapted to reduce an impact that the dust lip receives from the shaft when the shaft is inserted into the sealing device by making it possible to be hit by the shaft on its insertion is provided on the side of the dust lip opposite to the sealed area, the bumper portion and the seal main body are provided integrally with the reinforcing ring, and an inner diameter of a tip of the bumper portion on an inner peripheral side is set to be larger than an outer diameter of a part of the shaft on which the main lip and the dust lip may slide and to be smaller than an inner diameter of a part having the largest inner diameter in a portion connecting the main lip and the dust lip; and the bumper portion has a portion protruding radially inwardly having a sealed area side tapered surface of which the diameter is increased with approach to the sealed area side and an air side tapered surface of which the diameter is increased in a direction opposite to the sealed area side, and the sealed area side tapered surface faces a radially outer surface of the dust lip, characterized in that the bumper portion is constituted by part of the seal main body. a reinforcing ring having an inward flange portion; and a seal main body made of a rubber-like elastic body, provided integrally with the reinforcing ring, and having a main lip that extends from a vicinity of a tip of the inward flange portion to a sealed area side, and is adapted to slidably come into contact with an outer peripheral surface of the shaft, and a dust lip that extends from the vicinity of the tip of the inward flange portion to a side opposite to the sealed area, and is adapted to slidably come into contact with the outer peripheral surface of the shaft, wherein a bumper portion made of a rubber-like elastic body only and adapted to reduce an impact that the dust lip receives from the shaft when the shaft is inserted into the sealing device by making it possible to be hit by the shaft on its insertion is provided on the side of the dust lip opposite to the sealed area, the bumper portion and the seal main body are provided integrally with the reinforcing ring, and an inner diameter of a tip of the bumper portion on an inner peripheral side is set to be larger than an outer diameter of a part of the shaft on which the main lip and the dust lip may slide and to be smaller than an inner diameter of a part having the largest inner diameter in a portion connecting the main lip and the dust lip; and the bumper portion has a portion protruding radially inwardly having a sealed area side tapered surface of which the diameter is increased with approach to the sealed area side and an air side tapered surface of which the diameter is increased in a direction opposite to the sealed area side, and the sealed area side tapered surface faces a radially outer surface of the dust lip, characterized in that the bumper portion is constituted by part of the seal main body.