NOVELTY - A polyelectrolyte fuel cell (100) has polymer electrolyte membrane (102), gas-diffusion electrodes having gaseous-diffusion layers (103a,103b) arranged so that the polymer electrolyte membrane and catalyst layers (102a,102b) contact on both surfaces of electrolyte membrane, separators (105a,105b), and mesh sheets (108a,108b). The hydrophilic grade of portion opposing flow path of mesh sheet is less than the hydrophilic grade of flow path of separator and greater than the hydrophilic grade of portion opposing flow path of gaseous-diffusion layer.    USE - Polyelectrolyte fuel cell is used for cogeneration systems, industrial applications, and transport machines, such as motor vehicles and motorcycles.    ADVANTAGE - The polyelectrolyte fuel cell has excellent reliability, and outputs electric power stably over a long period of time. Retention of produced water on the gaseous-diffusion layer is prevented.    DETAILED DESCRIPTION - A polyelectrolyte fuel cell (100) consists of a polymer electrolyte membrane (102), a pair of gas-diffusion electrodes having gaseous-diffusion layers (103a,103b) arranged so that the polymer electrolyte membrane and catalyst layers (102a,102b) contact on both surfaces of the polymer electrolyte membrane, a pair of separators (105a,105b), and mesh sheets (108a,108b). The separator has a groove-shaped flow path for interposing the gas-diffusion electrodes and supplying a reactive gas to the gaseous-diffusion layer at the main surface. The mesh sheet is inserted between the gaseous-diffusion layer and main surface of separator. The hydrophilic grade of portion opposing the flow path of mesh sheet is less than the hydrophilic grade of flow path of separator and greater than the hydrophilic grade of portion opposing flow path of gaseous-diffusion layer.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of the polyelectrolyte fuel cell.    Polyelectrolyte fuel cell (100)    Polymer electrolyte membrane (102)    Catalyst layers (102a,102b)    Gaseous-diffusion layers (103a,103b)    Separators (105a,105b)    Mesh sheets (108a,108b)