A gas diffusion electrode comprisinga porous sheet substrate, at least the surface of which is formed by silver;a reaction layer formed on a first surface of the substrate, comprising a porous silver layer and a mixed layer further comprising a hydrophilic material and a hydrophobic material, the mixed layer being formed on a surface of the porous silver layer; and,a gas diffusion layer formed on a second surface of the substrate, comprising a hydrophobic material.The gas diffusion electrode can be stably used for, e.g., sodium chloride electrolysis for extended periods of time even under severe conditions.