Abstract: A muffler (1) for an exhaust system (2) of an internal combustion engine, especially of a motor vehicle, with a muffler housing (3), which encloses a housing interior space (5), and with at least one exhaust gas-carrying hollow body (4) with two half shells in a half shell construction. The hollow body is arranged in the housing interior space (5). The two half shells (14, 15) of the hollow body (4) are fastened to one another in the area of a separating plane (16). The assembly of the muffler (1) or of the hollow body (4) can be simplified if the two half shells (14, 15) are fastened to one another by fastening elements (17, 18), which are formed directly on the half shells (14, 15).