The base material for a gas diffusion electrode of the present invention comprises a nonwoven fabric containing conductive fibers that contain conductive particles at least in the inside of an organic resin, and is characterized in that a specific apparent Young's modulus of the base material for a gas diffusion electrode is 40 [MPa/(g/cm3)] or more. Since the base material contains conductive fibers that contain conductive particles at least in the inside of an organic resin, it is flexible, and as a result, a polymer electrolyte membrane is not directly damaged. Further, since the specific apparent Young's modulus is 40 [MPa/(g/cm3)] or more, which indicates a high rigidity, and swelling and shrinkage of the polymer electrolyte membrane can be inhibited, cracking of the polymer electrolyte membrane can be avoided.