PURPOSE: To resolve a problem concerning direct electrification heating, enable rapid heating, improve ventilating property and anti-oxidization property, and also eliminate necessity of the electrode for electrification.

CONSTITUTION: A porous body 12 made of silicon carbide is provided on the way of an exhaust gas flow passage 10 in such a manner as crossing the inside of the flow passage 10. A micro-wave radiation port 14 is opened on the pipe wall part of the flow passage 10, and a magnetron 18 is arranged on the outside of the micro-wave radiation port 14 through a wave leading pipe 16. A catalyst carrier 20 on which an exhaust gas purifying catalyst is carried is provided downstream from the porous body 12 made of silicon carbide. It is thus possible to make rapid heating, improve anti-oxidization property and durability, and also eliminate necessity of the electrode for electrification. And also it is possible to eliminate harmful component in exhaust gas effectively from just after start of an engine.