TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The catalyst material is three-dimensionally dispersed and carried at a surface of and inside the porous carbon frame. The catalyst material is selected from the platinum oxide, complex oxide of platinum and metal element other than platinum, platinum or platinum-containing multi-metal element obtained through reduction of the platinum oxide or the complex oxide, a mixture of platinum and oxide of metal element other than platinum, and a mixture of platinum-containing multi-metal element and oxide of metal element other than platinum. The catalyst material comprises whiskers having an average thickness of 5 - 50 nm, or flaky parts having an average thickness of 5 - 50 nm. The catalyst material has a structure containing whisker and a flaky nanostructural unit. The porous carbon frame comprises carbon powder and a binder containing a solid polymer electrolyte. The carbon fibers are nanotubes or nanofibers. The carbon fibers have an average diameter of 5 - 500 nm and an average length of 1 - 100 microns. Preferred Process: In the process (P1), the carbon fibers are formed by thermal chemical vapor deposition. EXAMPLE - VGCF (RTM: carbon powder), Nafion (RTM: solid polymer electrolytic solution), isopropyl alcohol (IPA) were mixed and dispersed in a predetermined mixing ratio to obtain a slurry (a). The slurry (a) was is applied onto a polytetrafluoroethylene (PTFE) sheet as a transfer layer with respect to the polymer electrolytic membrane by means of a doctor blade to obtain a porous carbon frame as a supporting member (b). The supporting member (b) was moved in a sputtering apparatus and subjected to film formation of a catalyst material of platinum 26 oxide having a structure comprising whiskers or a structure comprising flaky parts at a thickness (rate) of 0.25 mg/cm2. After an inner pressure of a sputtering chamber was reduced to a pressure of 1x10-4 Pa, argon and oxygen were introduced in the sputtering chamber at flow rates of 2.5 standard cubic centimeters per minute (sccm) and 20.0 sccm, respectively, and a total pressure was adjusted to 6 Pa at an orifice. Reactive sputtering was effected with supplied power of 4 W/cm2 to form, on the porous carbon frame, a film of platinum oxide of the structure comprising whiskers or the structure comprising flaky parts at a thickness (rate) of about 0.25 mg/cm2. The supporting member had sufficient pores and holes, such that the sputtered catalyst material of platinum oxide was three-dimensionally dispersed and disposed not only at the surface of the porous carbon frame but also inside the porous carbon frame. The supporting member after completion of the film formation was exposed to 2% H2/He at 10 kPa was easily subjected to reduction. After the reduction, IPA was added dropwise to the supporting member in an amount of 0.3 cc/cm2 to dissolve Nafion (RTM: solid polymer electrolytic solution) in the porous carbon frame, followed by drying in an atmosphere of ambient air to cause mutual binding of Nafion (RTM: solid polymer electrolytic solution) again to obtain a cathode-side catalyst electrode (c). Hi SPEC 4000 (RTM: platinum-supported carbon), Nafion (RTM: solid polymer electrolytic solution), and IPA were mixed in a predetermined mixing ratio to obtain a slurry (d). The slurry (d) was applied onto a PTFE sheet as a transfer layer with respect to the polymer electrolytic membrane to obtain an anode-side catalyst electrode (e). Nafion (RTM: solid polymer electrolytic solution) was sandwiched between the cathode-side catalyst electrode (c) and anode-side catalyst electrode (e) and then was subjected to hot pressing. After, the PTFE sheets were removed, such that the pair of catalyst electrodes was transferred onto the solid polymer electrolytic membrane to a catalyst electrode (E2). A catalyst electrode (E2) was sandwiched between LT 1400-W (RTM: gas diffusion layers of carbon cloth) and was further sandwiched between a fuel electrode and an air electrode to obtain a polymer electrolyte fuel cell (test). A control polymer electrolyte fuel cell was prepared similarly except that the sputtering of platinum oxide was directly effected with respect to the gas diffusion layer without using the porous carbon frame. The test/control polymer electrolyte fuel cells were then evaluated for cell properties in terms of limiting current density and cell voltage. The results for test/control polymer electrolyte fuel cells were: limiting current density (A/cm2): 0.327/0.212, cell voltage (V) = 0.617/0.542 (at 0.1 A/cm2) and cell voltage (V) = 0.400/0.310 (at 0.2 A/cm2) respectively. The results showed that the test polymer electrolyte fuel cell exhibited excellent cell properties as compared to the control polymer electrolyte fuel cell.