This base material for a gas diffusion electrode includes a nonwoven containing conductive fibers containing conductive particles at least inside an organic resin, wherein said base material is characterized in that the apparent Young's modulus of the base material for a gas diffusion electrode is 40 MPa/(g/cm<3>) or greater. Thus, because the base material for a gas diffusion electrode contains conductive fibers containing conductive particles at least inside an organic resin and is accordingly flexible, a solid polymer film is not directly damaged, the apparent Young's modulus is 40 MPa/(g/cm<3>) or greater indicating high rigidity, and expansion and contraction of the solid polymer film can be mitigated, making it possible to prevent cracking of the solid polymer film.