Abstract: A silencer includes: a porous inner pipe provided in a peripheral wall thereof with a large number of small pores; an outer pipe surrounding the porous inner pipe; a sound absorbing material incorporated in an annular clearance between the porous inner pipe and the outer pipe; and a plurality of exhaust gas expansion chambers defined in the porous inner pipe and arranged such that an exhaust gas is sequentially passed through the exhaust gas expansion chambers. The sound absorbing material is formed of a heat-resistant fiber layer which is wound around an outer peripheral surface of the porous inner pipe with a binder interposed therebetween, and an outer peripheral surface of the heat-resistant fiber layer is press-fitted to an inner peripheral surface of the outer pipe with a predetermined interference. Thus, it is possible to prevent a reduction in sound vanish effect due to the leakage and short-circuiting of an exhaust gas and a reduction in engine power performance.