A cylindrical gasket 27 includes a reinforcing member 70 made from a compressed belt-shaped metal wire net 5, a heat-resistant material 71 filled in meshes of the belt-shaped metal wire net 5 of the reinforcing member 70, and pores which are dispersedly distributed in the reinforcing member 70 and the heat-resistant material 71. An inner peripheral surface 23, an outer peripheral surface 24, and annular end faces 25 and 26 of the cylindrical gasket 27 are each formed by a smooth surface in which the heat-resistant material 71 and the reinforcing member 70 are present in mixed form. In the cylindrical gasket 27, the volume contents of the reinforcing member 70, the heat-resistant material 71, and the pores are 32 to 60%, 5 to 58%, and 10 to 35%, respectively.