A flat electrode structure for use in alkaline fuel cell stacks has electrolyte and gas inlet and outlet manifolds, with the gas manifolds being at the sides of the electrode. There is at least one gas inlet manifold and one gas outlet manifold in each side frame, and electrolyte and gas flow channels formed in the top and bottom, and side frame members. Side-to-side gas flow of the fuel gas or oxidizer gas across the electrode face is effected, with bottom to top electrolyte flow. In another embodiment of electrode structure, an embedded metal frame around the electrode serves as a current collector while stiffening the frame so as to reduce thermal expansion.