The present invention provides a process for producing a perovskite-type oxide catalyst. The process comprises the steps of reacting an aqueous solution containing plural metal salts, such as chloride, sulfate, nitrate, etc., and an aqueous solution of a neutralizer such as alkali carbonate, alkali hydroxide, ammonia, etc., so as to cause coprecipitation of neutral salts and firing the coprecipitated salts to provide a perovskite-type oxide. At least one organic substance selected from the group consisting of cellulose, polyvinyl acetate, polyethylene, polystyrene, polypropylene, polyvinyl alcohol, starch, gelatin and saccharide is added prior to the firing step. The addition of the organic substance makes possible the attainment of a highly active perovskite-type oxide catalyst composed of very fine particles (primary particles).