This specification discloses a thin-film gas diffusion electrode (GDE) and the method for making the same. The thin-film GDE is formed in a unitary way. A dual-nature porous thin film is used as the substrate. A surface processing is performed to make one surface of the thing film hydrophlic while the other surface hydrophobic. The hydrophlic area serves as the active layer for electrochemical reactions after chemical processing. The hydrophobic area is kept dry to form a smooth gas channel, functioning as a gas diffusion layer. In this method, the thin-film GDE is free from the use of binders and high-temperature high-pressure manufacturing processes.