A fuel cell electrode structure includes a membrane electrode assembly including an electrolyte membrane between a pair or electrodes, and a frame being integrally formed with the membrane electrode assembly supporting the membrane electrode assembly from the peripheral side.The membrane electrode assembly includes a gas diffusion layer on the surface, and a sealing member for sealing the periphery of the membrane electrode assembly is provided on the frame.The sealing member includes a lip portion, and at least partly includes extended portion that extends to the membrane electrode assembly. The extended portion is thinner than the lip portion of the sealing member, and the end face of the extended portion is in contact with the end face of the gas diffusion layer.