GAS DIFFUSION ELECTRODE AND METHOD FOR PRODUCING SAME

The present invention provides a gas diffusion layer for a fuel cell that is balanced between performance and durability. The present invention provides a gas diffusion electrode having a microporous layer, wherein the microporous layer has at least a first microporous layer and a second microporous layer, the first microporous layer has a cross-sectional F/C ratio of 0.06 or more and 0.33 or less, the second microporous layer has a cross-sectional F/C ratio less than 0.06, and wherein the first microporous layer is equally divided into a part not in contact with the second microporous layer and a part in contact with the second microporous layer, in the equally divided first microporous layer. The part not in contact with the second microporous layer is referred to as a microporous layer 1-1, the part in contact with the second microporous layer is referred to as a microporous layer 1-2, and the microporous layer 1-1 has a cross-sectional F/C ratio smaller than that of the microporous layer 1-2, wherein "F" is the mass of fluorine atoms, "C" is the mass of carbon atoms, and the "cross-sectional F/C ratio" is the value of "mass of fluorine atoms"/"mass of carbon atoms" as measured in the cross-sectional direction.