NOVELTY - Polyimide resin has specific basic structure (1).    USE - For electrolyte film and catalyst layer used for film-electrode joint component used for electrolysis cell, electrochemical sensors such as hydrogen sensors and carbon monoxide sensors, fuel cell (all claimed) such as polymer electrolyte fuel cells (PEFC) and direct-type methanol fuel cells (DMFC) used as power supplies for electric vehicles and domestic portable devices.    ADVANTAGE - The electrolyte film using the polyimide resin, has excellent oxidation resistance, hydrolysability-proof property, durability, proton conductivity and mechanical strength. Fuel cell with the film-electrode joint component having the electrolyte film, has high performance.    DETAILED DESCRIPTION - Polyimide resin has basic structure of formula (1).    Ar1,Ar2=6-20C aromatic ring having portion of carbon atom optionally substituted by sulfur, nitrogen, oxygen, sulfur dioxide or carbon monoxide, and portion of H optionally substituted by aliphatic group, halogen atom or perfluoro aliphatic group, and 5 or 6 membered imide ring of adjacent imide group is formed;    Ar3=6-20C aromatic ring having at least one portion of H optionally substituted by 1-20C sulfo alkoxyl group having portion of carbon atom optionally substituted sulfur, nitrogen, oxygen, sulfur dioxide or carbon monoxide, and portion of H optionally substituted by aliphatic group, halogen atom or perfluoro aliphatic group;and    n,m=degree of polymerization, and are integer greater than 1.    INDEPENDENT CLAIMS are included for the following: (i) manufacture of the polyimide resin, which involves heat-dissolving mixture of 4,4'-(9-fluorenylidene) dianiline, diamino compound of formula: H2N-Ar3-NH2, and tertiary amine in organic solvent, adding and polymerizing aromatic tetracarboxylic-dianhydride of formula (4 or 5) with respect to the heat-dissolved mixture, and heating the resulting product at 40degreesC or more in the presence of organic acid; (ii) electrolyte film, which contains the polyimide resin; (iii) catalyst layer (12A,12B), which contains the polyimide resin and predetermined catalyst; (iv) film-electrode joint component (11), which is obtained by joining the electrolyte film and the catalyst layer; (v) fuel cell, which has film-electrode joint component; (vi) electrolysis cell, which has the film-electrode joint component; and (vii) electrochemical sensor, which has the film-electrode joint component.    Ar3=same as defined above;and    Ar1,Ar2 of formula (4 or 5)=6-20C aromatic ring having portion of carbon atom optionally substituted by sulfur, nitrogen, oxygen, sulfur dioxide or carbon monoxide, and portion of H optionally substituted by aliphatic group, halogen atom or perfluoro aliphatic group, and 5 or 6 membered anhydrous carboxylic acid ring of adjacent anhydrous carboxylic acid group is formed.    DESCRIPTION OF DRAWING(S) - The figure shows the block diagram of the fuel cell.    film-electrode joint component (11)    catalyst layers (12A,12B)    anode side gas diffusion electrode (14A)    cathode side gas diffusion electrode (14B)