PURPOSE: To improve the purifying effect of the exhaust gas by consisting a rod-shaped electrode of a cylindrical body where an opening is formed at its upstream end part and its downstream end part is closed, and forming a plurality of communicating holes in the circumferential wall of the cylindrical body and a plurality of holes in a catalyst body.

CONSTITUTION: An exhaust emission control system 1 is provided with an outer cylinder 4 composed of a conductive material and a conductive monolithic catalyst 5 stored therein. A rod-shaped electrode 6 consists of a cylindrical body where an opening 8 is formed at its upstream end part, and the downstream end part is closed. A lot of communicating holes 10 are formed in a circumferential wall 9 of the cylindrical body. A lot of communicating holes are formed in the foil-shaped metal consisting of the conductive monolithic catalyst 5. The exhaust gas flowing into the cylindrical body flows through a lot of communicating holes 10 to the conductive monolithic catalyst 5, and through the communicating holes in the foil-shaped metal, and is diffused into the conductive monolithic catalyst 5. Thus, the purifying effect of the exhaust gas can be improved.