PURPOSE: To obtain a catalyst having high cleaning function at low temperature and high durability by coating a monolithic carrier with a slurry containing carbon black and a zeolite ion-exchanged with a transition metal.

CONSTITUTION: A slurry is prepared from a zeolite powder which is ion- exchanged with a transition metal such as copper, cobalt, etc., an inorganic binder, water, and carbon black. The slurry is applied to a monolithic carrier, dried, and sintered. By this method, a large number of through holes are formed in the binder parts of a metal-zeolite layer. Consequently, a waste gas can come to inside of the metal-zeolite layer and cleaning function of the catalyst at low temperature is improved.