NOVELTY - Fuel cell (201) has a membrane-electrode composite including proton-conductive electrolyte film (204) which has fuel electrode formed on one surface and air electrode formed on other surface. The fuel electrode has catalyst layer (202) and conductive layer (203). The catalyst layer contains electrode catalyst (207) and electrolyte composition (208). The proton conduction resistance per fuel-electrode projection unit area of catalyst layer, is 20 mohm.cm2 or less. The weight per fuel-electrode projection unit area of electrode catalyst is 3-100 mg/cm2.    USE - Fuel cell used for electronic devices (claimed) such as mobile telephone, electronic notebook and notebook personal computer. Fuel cell is polymer electrolyte fuel cell and direct methanol type fuel cell.    ADVANTAGE - Fuel cell has stable and favorable power generation characteristics.    DETAILED DESCRIPTION - Fuel cell has a membrane-electrode composite including proton-conductive electrolyte film which has fuel electrode formed on one surface and air electrode formed on other surface. A liquid fuel chamber is provided for supplying liquid fuel to fuel electrode. The fuel electrode has catalyst layer and conductive layer. The fuel-electrode catalyst layer contains electrode catalyst and electrolyte composition having proton conductivity. The proton conduction resistance per fuel-electrode projection unit area of catalyst layer, is 20 mohm.cm2 or less. The weight per fuel-electrode projection unit area of electrode catalyst is 3-100 mg/cm2. The electrolyte composition is liquid electrolyte, or solid electrolyte dissolved in liquid fuel. The liquid electrolyte is sulfuric acid or ionic liquid. The solid electrolyte is perfluoro group solid polymer electrolyte, hydrocarbon group solid polymer electrolyte or inorganic solid acid.    DESCRIPTION OF DRAWING(S) - The drawing shows the sectional view of portion of side of fuel electrode of fuel cell.    Fuel cell (201)    Fuel-electrode catalyst (202)    Fuel-electrode conductive layer (203)    Electrolyte film (204)    Electroconductive substance (206)    Electrode catalyst (207)    Electrolyte composition (208)