Provided is a non-noble metal-based exhaust gas purifying catalyst which is capable of removing an unreacted material such as carbon monoxide in an exhaust gas at low temperatures. An exhaust gas purifying catalyst of the present invention contains a ceria-based carrier and a complex oxide of cobalt and an additional metal element, said complex oxide being supported by the ceria carrier. The additional metal element contains a metal element that is selected from the group consisting of copper, silver, magnesium, nickel, zinc and combinations of these elements.