In order to form a film of cerium oxide containing metal atoms dispersed, together, characterized in that it is sputtered onto the substrate from at least one target under an argon atmosphere, and cerium oxide, the metal material and cerium oxide, gold, by sputtering to the substrate from the target metal oxide and cerium oxide catalyst having a metal being selected from the group consisting of platinum, palladium, tin, nickel or ruthenium, the process for preparing. Pt-CeO2 catalyst and Au-CeO2 particular is prepared by using this method.