PURPOSE: To increase the surface area or an electrode by coating a cathode agent on one face of a separator and an anode agent on the other face and bringing respective faces into contact with a cathode and an anode.

CONSTITUTION: A porous layer 7 made of a cathode agent is formed on one face of a separator 5, a porous layer 8 made of an anode agent is formed on the other face, the separator 5 is inserted between a cathode 2 and an anode 3, and the layers 7 and 8 are brought into contact with the cathode 2 and the anode 3 respectively. On the other hand, an electrolyte plate 1 is pinched by the cathode 2 and the anode 3 from both sides, oxidizing gas is fed to the cathode 2 side and fuel gas is fed to the anode 3 side. The porous layers 7 and 8 are brought into contact with the cathode 2 and the anode 3 at projections, the electrolyte of the electrolyte plate 1 infiltrates through respective contact points A and B, and the area of the electrode is increased.