NOVELTY - A catalyst electrode (E1) comprises a catalyst material (2); and a porous carbon frame (3) or carbon fibers for carrying catalyst material. The catalyst material has a nanostructure containing whiskers or flaky parts. The porous carbon frame has pores having a pore diameter of 0.5 - 10 microns in terms of a mode diameter; and has a porosity of 12 - 80%.    USE - As a catalyst electrode useful in polymer electrolyte fuel cell (claimed); in automobiles, home power generators, mobile phone, notebook computer and digital camera.    ADVANTAGE - The catalyst electrode improves activity polarization, resistance polarization and diffusion polarization; improves the catalyst activity to provide a fuel cell having excellent cell properties; improves performances of the polymer electrolyte fuel cell; improves utilization rate of catalyst material; improves fuel cell performances by formation of a good three-phase interface and suppression of flooding of electrode due to produced water. The production process of the catalyst electrode is a simple and in expensive process with good reproducibility, such that it is possible to realize a polymer electrolyte fuel cell having a stable property at low cost. The production process of the catalyst electrode provides a polymer electrolyte fuel cell having an electric power generation property, which is uniform and stable for a long period of term.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) producing the catalyst electrode (E1) involving a step of forming the catalyst material at surface of or inside the porous carbon frame by sputtering, vacuum deposition or ion plating in a vapor phase, or a step of forming the catalyst material by reactive vacuum deposition;    (2) a polymer electrolyte fuel cell comprising the catalyst electrode (E1), and a solid polymer electrolyte disposed adjacent to said catalyst electrode.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional structure of a single cell of a polymer electrolyte fuel cell using a catalyst electrode.    solid polymer electrolyte membrane (1)    catalyst material (2)    porous carbon frame (3)    cathode-side gas diffusion layer (6)    cathode-side collector. (8)