TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The proton acid group-containing aromatic polymer contained in the catalyst layer is a sulfonated polyarylene having aromatic group-containing structural unit (A) and structural unit (B).Y = -CO-, -SO2-, -SO-, -CONH-, -COO-, -(CF2)i- or -C(CF3)2-;Z = direct bond, -(CH2)j-, -C(CH3)2-, -O- or -S-;Ar = aromatic group having substituent of formula -SO3H, -O(CH2)pSO3H or -O(CF2)pSO3H;p = 1-12;m and n = 0-10;k = 1-4;A and D = direct bond, -CO-, -SO2-, -SO-, -CONH-, -COO-, -(CF2)i-, -(CH2)j-, -CR'2-, cyclohexylidene group, fluorenylidene group, -O- or -S-;i and j = 1-10;R' = aliphatic hydrocarbon, aromatic hydrocarbon or halogenated hydrocarbon;L = oxygen atom or sulfur atom;R1-R16 = H, fluorine atom, alkyl, halogenated alkyl by which portion(s) of alkyl is halogenated, allyl, aryl, nitro or nitrile group;s and t = 0-4;andr = 0, 1 or more integer.The proton acid group-containing aromatic polymer contained in the adhesive layer is same as the proton acid group-containing aromatic polymer contained in the catalyst layer. The adhesive layer further contains electroconductive filler. The adhesive layer contains proton acid group-containing aromatic polymer and electroconductive filler in mass ratio of 5/95-60/40. EXAMPLE - A catalyst paste composition was prepared using YTZ ball (RTM: zirconia ball), TEC10E50E (RTM: platinum-supported carbon particles), 15% N-methyl-2-pyrrolidone solution of sulfonated polyarylene (II), N-methyl-2-pyrrolidone and DA234 (RTM: dispersant). An adhesive agent composition was prepared using YTZ ball (RTM: zirconia ball), Ketchen Black EC (RTM: carbon black), 15% N-methyl-2-pyrrolidone solution of sulfonated polyarylene (IV), N-methyl-2-pyrrolidone and DA234 (RTM: dispersant). The prepared catalyst paste composition and adhesive agent composition were applied on carbon paper. Subsequently, a gaseous diffusion layer was formed and interposed into the catalyst layer formed using the catalyst paste composition. The catalyst layer was formed on both surfaces of a polymeric electrolyte film, and a membrane electrode assembly was produced. The membrane electrode assembly had excellent electric power generation durability. The sulfonated polyarylenes (II,IV) were prepared using 3-(2,5-dichloro benzoyl)-neopentyl benzene sulfonate, bis(triphenyl phosphine)nickel dichloride, sodium iodide, triphenyl phosphine and zinc as main components. The sulfonated polyarylene (II) had ion exchange capacity of 2.3 meq/g and weight average molecular weight of 135000. The sulfonated polyarylene (IV) had number average molecular weight of 102000, weight average molecular weight of 320000 and ion exchange capacity of 2.1 meq/g.