TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The polymer preferably comprises pyrazino quinoxaline compound having formula (2) in a side chain or pyrazino quinoxaline-repeating units having formulae (3-6).R7-R36 = same as R1-R6.Preferred Properties: The weight average molecular weight of the polymer measured by light scattering is 5000 or more. The polymer comprises units (in mass%) (5 or less) having an absolute molecular weight less than 1000.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Carbon Material: The electroconductive carbon material is carbon black, activated carbon, carbon fiber and/or graphite.Preferred Electrolyte: The electrolyte is solid and/or gel electrolyte having proton conductivity, or sulfuric acid solution (10-50).Preferred Properties: The electroconductive carbon material has an electric conductivity of 0.1 S/cm or more at 20-30degreesC, Brunauer Emmett Teller specific surface area of 50-5000 m2/g, and mean particle diameter of 0.5-30 mum. The composite has volume electric conductivity of 0.1 S/cm or more at 25degreesC, mean particle diameter of 1-20 mum, and mean particle size of 200 mum or less. The decrease in volatile mass of the composite after one hour at 150degreesC and 50000-150000 Pa, is 5 mass% or less.Preferred Composition: The electroconductive carbon material comprises fibrous carbon material (1-40), such as vapor phase epitaxy carbon fiber with a diameter of 1 mum or less, or carbon nanotube, having an aspect ratio of 5 or more. The mass composition ratio of electroconductive carbon material and the polymer is 8:92-30:70. The composite comprises halogen impurity (1 or less), metal impurity (0.5 or less) and ionic impurity (1 or less), with respect to the total composition.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compounds: The tetracarbonyl compound comprises two alpha, beta-dicarbonyl groups having formula (8).R39-R44 = same as R1-R6.Preferred Process: The dehydration condensation polymerization of tetraamino benzyl derivative and tetracarbonyl is performed in presence of a solvent containing water (2), at 50-250degreesC and agitating speed of 150-500 rpm, for 15-100 hours.Preferred Solvent: The solvent is N,N-dimethylformamide, N-methyl pyrrolidone, tetrahydrofuran, 1,2-dimethoxy ethane, triethyleneglycol dimethylether and/or tetraethylene glycol dimethylether.Preferred Composition: At the start of the reaction the reaction raw material comprises tetraamino benzene derivative and tetracarbonyl compound (5-40), respect to the solvent. EXAMPLE - N,N-dimethylformamide and ethanol were poured into a reaction container. 1,4-bisbenzyl having weight average molecular weight of 342.4 and 1,2,4,5-tetraamino benzene were added to the container, stirred in room temperature and nitrogen atmosphere for 30 minutes to completely dissolve 1,4-bisbenzyl and 1,2,4,5-tetraamino benzene. KB-EC (kitchen black) and tetraethylene diamine were added to the dissolved mixture and reacted for 30 hours at 100degreesC. A black precipitate was obtained. The precipitate was filtered, washed with methanol, and vacuum dried at 120degreesC for 12 hours to obtain polyphenyl pyrazino quinoxaline/kitchen black composite. The compounding ratio of polyphenyl pyrazino quinoxaline to kitchen black was 95:5. Polyphenyl pyrazino quinoxaline had an absolute molecular weight of 70000. The composite has an electric conductivity of 0.5 S/cm, at 25degreesC. The composite was then ground. The composite had an average particle diameter of 15 mum, average particle size of 120 mum and contained 230 ppm of halogen impurity and 80 ppm of metal impurity. The decrease in volatile mass of the composite after one hour at 150degreesC and 50000-150000 Pa, was 0.5 mass%.