A silencer comprising an outer sleeve made of a aluminum or an aluminum alloy, an inner sleeve made of a iron or steel, and acoustic material inserted between the outer sleeve and the inner sleeve. An end cap for closing a downstream end of the silencer comprising a first member made of iron or steel which is formed into a shape of the end cap, and a second member made of aluminum metal which is formed into the same shape as the outline of the first member, the peripheral portion of the first member and the peripheral portion of the second member being laminated. An end plate made of aluminum being mounted on an upstream end of the silencer. Clamping members made of iron or steel including female or male screws are secured to the end plate. An exhaust pipe is provided with a mounting seat at a fixed position thereof. The silencer can be secured to the mounting seat by means of the clamping members and bolts or nuts made of iron or steel. The end cap can be welded to a part of the outer sleeve. Caulking is not necessary in the last process of production of the silencer. Since on the upstream side, the silencer can be connected with an exhaust pipe by connection of iron or steel clamping members, even in the case where the clamping members are thermally expanded, it is possible to improve dependability on connection of the silencer with an exhaust pipe.