PURPOSE: To provide an electrode having no crack of a reaction layer by impregnating a reaction layer material sheet with a platinum group compound solution prior to the heating and pressurizing of the sheet, and adhering the heated platinum group metal or platinum group oxide to a hydrophilic carbon black.

CONSTITUTION: A wet mixture of a hydrophilic carbon black, water-repellent carbon black, a polyethylene tetrafluoride, and a surfactant is filtered to form a cake. A solvent is made to permeate the cake followed by rolling to form a reaction layer material sheet. Prior to the heating and pressurizing of the reaction layer material sheet, the reaction layer material sheet is dried to remove the surfactant and the solvent. Then, the reaction layer material sheet is impregnated with a platinum group compound solution to support a platinum group metal or a platinum group oxide. When the resulting sheet is then heated and pressurized to form a gas diffusion electrode 6 consisting of only a reaction layer 5, a gas diffusion electrode prevented from causing a crack by the heating and pressurizing can be provided since the reaction layer material sheet has a space or reactive margin for sufficiently receiving the carried material.