To conduct exhaust emission control by providing a combustion device to a muffler.

This combustion muffler carries out exhaust emission control without changing a structure of an internal combustion engine. A catalyst is disposed at inlet and outlet of the muffler, and the combustion muffler is provided with a purifying technology using the action of the catalyst and taking compressed oxygen into the muffler and combining the oxygen with high temperature exhaust gas to be burned. The widely acceptable combustion muffler also functions as a silencer whatever its form or distinction is.