In a sealing device of the present invention, a support ring is fitted in an annular recessed part formed on the inner peripheral surface of a seal lip part independently of a reinforcement ring to support the seal lip part from the inner peripheral side, and the support ring is supported axially by a reinforcement ring via an interposed part. Thereby, when a rotating shaft is inserted into the seal ring, a contact area between a seal part and the rotating shaft can be made appropriate, and when a high pressure is applied to the seal lip part, an increase in contact area between the seal part and the rotating shaft can be suppressed within an appropriate range and the seal part becomes able to follow the eccentricity of the rotating shaft.