PURPOSE: To provide the titled catalyst capable of removing CO, HC, NOx in the exhaust gas contg. excess oxygen by specifying the amt. of Pt, Rh, Pd, Ce, Pr, Cu, Ni, and Zr to be supported on a carrier basing on the amt. of alumina supported by the carrier.

CONSTITUTION: Alumina contg. oxides of at least one kind of heavy metal selected from Ce, Pr, Cu, Ni, and Zr is prepd., and coated on honeycomb carrier. Then, noble metals i.e. Pt, Rh, and Pd are deposited thereto. In this case, proportions of these metals basing on the alumina layer are by wt%; 0.70W0.90 Pt, 0.07W0.15 Rh, 0.07W0.75 Pd, 4.0W45 Ce, 10W25 Pr, 10W25 Cu, 10W20 Ni, and 10W20 Zr. With this catalyst, CO, HC, and NOx in the exhaust gas are removed simultaneously in an atmosphere contg. excess oxygen with high efficiency.