Fuel cell

A fuel cell (10) comprised of a solid electrolyte layer (18a) sandwiched by a cathode layer (18b) and an anode layer (18c) to which a mixed gas of a fuel gas and air mixed together is supplied, wherein the fuel cell (10) is formed into a spiral member (16) comprised of a single cell layer comprised of the cathode layer (18b), solid electrolyte layer (18a), and anode layer (18c) stacked together or a multilayer member of a plurality of the single cell layers stacked together rolled up spirally. The cathode layer (18b) and anode layer (18c) forming facing surfaces of each upper stratum and lower stratum of the single cell layer or multilayer member adjoining each other in a diametrical direction of the spiral member are arranged through an electrical insulator (20), and the cathode layer (18b) and anode layer (18c) or the electrical insulator (20) are or is formed with a gas passage enabling passage of the mixed gas. In this way it is possible to prevent an increase in size of the cell (10) when increasing the contact area of the anode layer (18c) and cathode layer (18b) with the air or fuel gas.