A bladder-type jig which is suitably used for manufacturing a stiffened panel structure using a hat stringer, and improves durability of the jig to enable repeated use of the jig. A body which is a body of a bladder has a hollow pipe-shape inside thereof. One end portion of the body is sealed by a terminal metal member, and the interior of body is in an air-tight condition. An insertion portion of the terminal metal member is inserted into a hollow space of the end portion of the body. A plurality of band-shaped groove portions are provided on the outer peripheral surface of the insertion portion such that the groove portions are wound around the outer peripheral surface. The band-shaped groove portions form a plurality of annular adhesive layers between the inner surface of the body and the outer peripheral surface of the insertion portion. This makes it possible to enhance an adhesive state between the body and the terminal metal member and air tightness in the interior of the body.