Fuel cell device

A fuel cell device (10) comprises: two vertically arranged cylindrical fuel cells (10a,10b) different in diameter, each comprising a solid-electrolyte layer (12a) having first and second surfaces, an anode layer (12b) formed on the first surface of the solid-electrolyte layer (12a), and a cathode layer (12c) formed on the other surface of the solid-electrolyte layer (12a). The two fuel cells are mutually arranged in such a manner that the anode layer of one of the fuel cells faces the anode layer (12b) of the other fuel cell (10b) with a predetermined space (14) between them and the space (14) extends vertically from a lower position to an upper position. A fuel supply unit (16,20) is provided for supplying fuel into the space (14) at the lower position thereof so that a flame (18) is formed, in the space (14), in an upward direction in which the space (14) extends. The invention may be applied to a planar configuration.