An object of the present invention is to provide a gasket capable of improving sealing performance by solving a non-uniform surface pressure distribution by a grommet structure. Provided is a gasket which is formed by laminating an upper layer, an intermediate layer, and a lower layer and is provided with a penetration hole and a seal bead formed at the upper layer and the lower layer to surround the penetration hole in a ring shape and to be symmetrical with respect to the intermediate layer in the vertical direction, in which the intermediate layer includes a fold-back portion, a surface pressure adjustment portion, and a bead contact portion, a plate thickness of the fold-back portion is thicker than that of the bead contact portion, and the surface pressure adjustment portion sets an upper step to be different from a lower step.