In a molten carbonate fuel cell wherein a cathode and an anode of porous material formed in contact with an electrolyte layer, each of the cathode and anode comprises a bilayered structure having a first porous layer located at the side of the electrolyte layer and a second porous layer at the side of an element for supplying a fuel (or oxidant) gas and consisting of a sintered layer of a fibrous material. Pores in at least a portion of the first porous layer, which is adjacent to the electrolyte layer, have a size allowing capillary action of a molten carbonate, and pores of the second porous layer have a size not allowing capillary action.