GAS DIFFUSION ELECTRODE SUBSTRATE FOR FUEL CELL, MEMBRANE ELECTRODE ASSEMBLY, AND FUEL CELL

摘要

[Problem] The present invention provides a gas diffusion medium for a fuel cell, which has low in-plane air permeability and good drainage property and is capable of exerting high cell performance across a wide temperature range from low to high temperatures. [Means for Solution] The gas diffusion medium for a fuel cell is characterized by comprising a microporous region [A], an electrode base material and a microporous region [B] that are arranged in the order mentioned, wherein the microporous region [A] has an areal ratio in the range of 5 to 70% and the microporous region [B] has an areal ratio in the range of 80 to 100%.