Patent ID: 7718303

Claim:
A membrane-electrode assembly for use in a fuel cell having a pair of separators for holding the membrane-electrode assembly therebetween, said membrane-electrode assembly comprising: a hydrogen-permeable metal layer containing hydrogen-permeable metal; an electrolyte layer with proton conductivity which is provided on the hydrogen-permeable metal layer; and a low thermal expansion member provided on a surface of the hydrogen-permeable metal layer, the surface being opposite to a surface of the hydrogen-permeable metal layer on which the electrolyte layer is provided, wherein a thermal expansion coefficient of the low thermal expansion member is lower than that of the hydrogen-permeable metal layer, and the low thermal expansion member includes a fitting portion which is formed having a recess portion on a surface of the low thermal expansion member on which the hydrogen-permeable metal layer is provided, and the hydrogen-permeable metal layer is fitted in the fitting portion.