PURPOSE: To reduce the material cost and the manufacture cost, improve the productive efficiency, and improve the yield by providing coated layers, laminating layers, and performing the heating to form a precompact, and performing the hot stabilizing treatment.

CONSTITUTION: Paper sheets, which are obtained by manufacturing paper from the slurry including a carbon fiber manufacturing organic fiber at 20-80weight% and pulp at 80-20weight%, are impregnated with the suspension, which is obtained by suspending the carbon material powder in the organic high polymer solution, to manufacture impregnated sheets 2a. Next, plural coated sheets 1a, to which the specified coating is performed, are pre-pressed to form a coated pre-pressed sheet (core layer) having 0.75-1.0g/cm2 of density, and plural sheets 2a are laminated in both sides of this sheet, and hot press is performed to form a precompact, and the hot stabilizing treatment and the hot burning treatment are performed thereto. A gas non-transmitting carbon layer and a phosphoric acid liquid storing porous carbon layer are thereby formed, and the material cost and the manufacturing cost are reduced to improve the productive efficiency and yield.