To make it unnecessary to insert a plate spring as a separate part between a metal ring (2) and a mating member (11) to be coupled therewith such as a clutch plate, and reduce the number of parts and the assembly manhours, the sealing device (1) includes the metal ring (2) and seal sections (3) such as packings supported by the metal ring (2), and the metal ring (2) is provided with a intimate-contact region (4) for intimately contacting to the mating member (11) to be coupled, wherein the sealing device (1) is characterized in that the intimate-contact region (4) of the metal ring (2) is integrally formed with pawl-like intimate-contact sections (6) which are in the form of a pawl and which exert spring force on the mating member (11) to be coupled, and is used, for example, as a bonded piston seal (BPS) in an automatic transmission.