PURPOSE: To uniformly distribute reaction gas to an electrode layer and make the electrode layer thin by arranging an electrode layer in which electrochemical reaction is performed on an electrode substrate formed with pore opened porous material having conductivity.

CONSTITUTION: Pore opened porous material having electroconductivity, large porosity and pore size and good gas passing ability is desirable as an electrode substrate 11. For example, foam metal of nickel or nickel fiber mat is used or it is manufactured by sintering nickel powder. An electrode layer 12 comprising nickel porous metal whose porosity and pore size are smaller and relative surface area is larger than those of the substrate 11 is formed together on the electrode substrate 11. The electrode layer 12 is manufactured by sintering fine nickel powder in a hydrogen furnace.