A fuel cell includes a separator having a circular disk. On one surface of the circular disk, a fuel gas channel is provided for supplying a fuel gas to an anode, and on the other surface of the circular disk, an oxygen-containing gas channel is provided for supplying air to a cathode. The fuel gas channel has an end point at an outer circumferential end of the anode. A fuel gas discharge channel is connected to an end point of the fuel gas channel, such that the consumed fuel gas is emitted to an oxygen-containing gas supply unit, from a position spaced outwardly from the outer circumference of an electrolyte electrode assembly.