Abstract: A method for filling a silencer with a sound absorbing material in which an inside of a shell is partitioned into a plurality of silencing chambers by a separator and at least one silencing chamber is filled with the material, the method including: forming a hole at the silencing chamber to be filled with the material in the shell; inserting a filling nozzle into the silencing chamber from the hole; injecting the material from the filling nozzle into the silencing chamber S2 for filling; and externally sealing the hole opening to the shell with a hole sealing member. An outer peripheral flange portion is abutted on and welded to an outer surface of the shell to seal the hole with the hole sealing member 8 allowing stably holding the silencer and easily filling the silencer with the material irrespective of a shell shape and a structure inside the shell.