An electrode for a fuel cell including a support and a catalyst layer formed on the support, wherein the catalyst layer comprises a supported catalyst and a polyurethane-based compound, wherein all or some of the polyurethane-based compound is synthesized from a polyol monomer where some or all of the polyol monomer is a polyol monomer that contains a phosphonyl group; a method of preparing the same; and a fuel cell including the same. The electrode for a fuel cell has excellent ion conductivity because it maintains stability at high temperature operation, and is capable of retaining phosphoric acid effectively even at high temperatures. A fuel cell can be prepared by using the electrode where the fuel cell can operate under these conditions of high temperature above 100° C. and no humidity and shows improved performance for generating electricity.