TECHNOLOGY FOCUS - POLYMERS - Preferred Properties: The decrease of weight when the polyelectrolyte material is immersed to 50degreesC N-methyl pyrrolidone for 5 hours is 30 wt.% or less. The sulfonic acid group density (as amount of sulfonic-acid-group) of the polyelectrolyte material is 0.5-3 mmol/g.Preferred Composition: The polyelectrolyte material contains crosslinkable compound (1-50 wt.pts) to hydrocarbon type (100 wt.pts) having ionic group. The hydrocarbon type polymer which has ionic group, has at least one type of ionic group selected from sulfonic acid group, sulfonimide group, sulfate group, phosphonic acid group, phosphoric acid group, and carboxylic acid group, preferably sulfonic acid group. The hydrocarbon type polymer which has ionic group is a non-bridge polymer, and contains at least one type of group selected from sulfonyl group, an oxy group, thio group, carbonyl group, phosphine-oxide group, phosphonic acid ester group, ester group, amide group, imide group and phosphazene group. The hydrocarbon type polymer which has ionic group consists of at least one type of selected from an aromatic carbonization aqueous polymer which has repeating unit of formula (P1).Z1,Z2 = organic group which contains aromatic ring;Y1 = electron-attractive group; andY2 = oxygen or sulfur; anda,b = 0-2 and are not 0 simultaneously.The polyelectrolyte type fuel cell is a direct type cell which uses at least one type selected from 1-6C organic compound and/or water as a fuel. Preferred Definitions:    R1=1-20C alkyl group or R2CO group;and    R2=1-20C alkyl group.    EXAMPLE - Hydrocarbon type polymer of formula (G2) (asterisk showing bonding) having sulfonic acid group density of 1.7 mmol/g and weight average molecular weight of 220000, was manufactured using potassium carbonate, 4-4'-(9H-fluorene-9-ylidene) bisphenol, 4,4'-difluoro benzophenone and disodium 3,3'-disulfonate-4,4'-difluoro benzophenone. Crosslinkable compound of formula (HMOM-TPPHBA) (in g) (1) was mixed with 25 wt.% N-methyl pyrrolidone (NMP) (16) solution in which hydrocarbon type polymer of formula (G2) having ionic group was dissolved. The resulting mixture was stirred at room temperature for 1 hour, applied on a glass substrate, dried at 100degreesC for 2 hours and heat-processed at 25degreesC under nitrogen atmosphere for 10 minutes. The polymeric electrolyte film was obtained. The obtained film was immersed in 1N hydrochloric acid for 24 hours, and proton substitution was performed, then immersed in pure water of excess amount for 24 hours and washed. The obtained film was red transparent. The film had decrease of the weight with respect to NMP of 4%, sulfonic acid group density of 1.4 mmol/g, haze of 14%, thickness of 33 microns and high ionic conductivity, and low methanol permeation amount.