CARBON SUBSTRATE COMPRISING CARBON FIBERS UNIDIRECTIONALLY ALIGNED, AND GAS DIFFUSION LAYER EMPLOYING SAME

Disclosed are a carbon substrate for a gas diffusion layer of a fuel cell, a gas diffusion layer employing the same, an electrode for a fuel cell, a membrane electrode assembly for a fuel cell, and a fuel cell, wherein the carbon substrate includes a plate-shaped substrate having an upper surface and a lower surface opposite the upper surface, and the plate-shaped substrate includes carbon fibers arranged to extend in one direction (extend unidirectionally) and a carbide of an organic polymer located between the carbon fibers to bind the carbon fibers to each other. Since the carbon substrate according to the present disclosure includes carbon fibers aligned in at least one direction selected from a machine direction (MD) and a cross-machine direction (CMD) by controlling the alignment of carbon fibers, the carbon substrate has excellent mechanical strength, particularly, bending strength, even if its thickness is thin, and thus it is possible to effectively prevent the intrusion phenomenon of the gas diffusion layer into the flow path of the metal separator, and has excellent gas flow characteristics.