Patent ID: 7351487

Claim:
A fuel cell comprising: a gas-permeable and electrically conducting support substrate having a fuel gas passage formed therein; a fuel-electrode layer formed on said support substrate; a solid electrolytic layer formed on said fuel-electrode layer so as to cover said fuel-electrode layer and containing ZrO 2 in which rare earth elements are existing in the form of solid solutions; and an oxygen-electrode provided on the solid electrolytic layer so as to face said fuel-electrode layer; wherein said support substrate is formed of a material consisting essentially of a metal of the iron family and/or an oxide of a metal of the iron family, and an oxide of at least one rare-earth element, and wherein said rare-earth element is selected from the group consisting of Y, Lu, Yb, Tm, Er, Ho, Dy, Gd, Sm and Pr, and said oxide of said rare-earth element is contained in said material of the support substrate in an amount of from 35 to 65% by volume.