The present invention is a solid oxide fuel cell 1 including a reforming section 94, disposed inside a fuel gas supply flow path 20 above a vaporizing section 86 to surround the upper portion of a fuel cell stack 14, for steam reforming raw fuel gas F introduced from a fuel gas introducing portion 90a using steam S produced in a vaporizing section; and a circulating flow path portion 156 disposed in a fuel gas supply flow path between the vaporizing section and the reforming section for circulating rising raw fuel gas introduced from a fuel gas introducing section into a fuel gas supply flow path and rising steam produced in the vaporizing section along the circumferential direction of the fuel gas supply flow path so as to form a flow supplying mixed raw fuel gas and steam uniformly over the entire circumference of the reforming section.