PURPOSE: To purify exhaust gas efficiently by forming a porous thin wall in a monolithic carrier formed of a micro-porous material and providing a filtering means with catalyst carried only on the site of inflowing side of said monolithic material.

CONSTITUTION: A monolithic carrier 4 is formed of a micro-porous material (example: cordierite), and a porous thin wall 8 is formed in said monolithic carrier 4, and also a filtering means 6 with catalysts 12 only on the site of inflowing side of the monolithic carrier 4 is provided. Thus, catalysts can be prevented securely from flying over generated by exhaust gas flow by the filter function of the filtering means 6, and the flowing speed of the catalyst performance can be made slower without flowing out the catalysts from the inside of the monolithic carrier of a converter 2 to purify exhaust gas efficiently.