NOVELTY - A gas diffusion electrode has an electroconductive region having gas diffusion function which allows gas to pass through, provided on at least one portion of a substrate (3), and a carbon catalyst (2) obtained by adhering carbon-precursor polymer on the electroconductive region and carbonizing.    USE - Gas diffusion electrode is used for membrane electrode assembly, fuel cell component and fuel cell (all claimed). Uses include but are not limited to polymer electrolyte fuel cell, alkali electrolyte-type fuel cell, phosphoric acid fuel cell, solid oxide fuel cell and bio fuel cell. Carbon catalyst is used for electrode material used for electrical storage apparatus (both claimed), and used for polymerization, hydrogenation, dehydrogenation, oxidation, modification and steam reformation.    ADVANTAGE - The gas diffusion electrode has improved electrical conductivity with respect to catalyst. The fuel cell formed using the gas diffusion electrode has improved electric power generation efficiency. The contact resistance of substrate and catalyst is improved. The carbon catalyst is economically manufactured with excellent chemical reaction efficiency.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) manufacture of gas diffusion electrode, which involves adhering carbon-precursor polymer on electroconductive region of substrate, and carbonizing;    (2) membrane electrode assembly, which has solid electrolyte and gas diffusion electrode arranged on both sides of electrolyte;    (3) manufacture of membrane electrode assembly, which involves integrating solid electrolyte and gas diffusion electrode;    (4) fuel cell component, which is formed by integrating the gas diffusion electrode and a separator;    (5) manufacture of fuel cell component;    (6) fuel cell, which has solid electrolyte and gas diffusion electrode arranged on both sides of solid electrolyte;    (7) electrical storage apparatus, which is formed by integrating electrode material formed using carbon catalyst, and electrolyte; and    (8) electrode material.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view of catalyst.    Catalyst (1)    Carbon catalyst (2)    Substrate (3)    Binder (4)