NOVELTY - A fuel cell has an electrolyte sandwiched by electrodes having a catalyst layer and/or gas diffusion layer. The catalyst layer comprises catalyst-bearing conductive power particles and fibrous carbon. The gas diffusion layer comprises a layer containing a water-repellent resin and a fibrous carbon. At least a portion of the gas diffusion layer surface is in contact with the catalyst layer.    USE - In fuel batteries (claimed) for power generation.    ADVANTAGE - The fuel cell enables simple humidification control, exhibits enhanced power-generating efficiency and enables reduction of contact resistance and enhancement of gas permeability and gas diffusibility.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) a catalyst composition comprising catalyst-bearing conductive powder particles and fibrous carbon;    (2) an electrode material comprising a conductive substrate and a catalyst layer which contains the catalyst composition;    (3) a polymer electrolyte fuel cell comprising a polymer electrolyte membrane and a pair of electrodes which sandwiched the electrolyte membrane, each electrode having a catalyst layer;    (4) a membrane-electrode assembly comprising an electrolyte membrane and an electrode having the catalyst layer and the gas diffusion layer, provided on each surface of the electrolyte membrane;    (5) the production of a layer assembly for a fuel cell, which involves forming a gas diffusion layer by applying a conductive porous substrate onto or immersing the conductive porous substrate in a composition comprising conductive powder particles, hydrophobic resin and fibrous carbon, forming an electrode by forming a catalyst layer comprising catalyst-bearing carbon particles on the surface of the gas diffusion layer, and bonding the catalyst of the electrode to each surface of an electrolyte membrane, where the composition is applied onto the surface of the gas diffusion layer or the gas diffusion layer is immersed in the composition; and    (6) a fuel battery comprising at least two fuel cells which are layered together.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of a gas diffusion sheet.