A water control sheet having superior drainage and gas diffusion properties and superior handling characteristics, and a gas diffusion sheet, a membrane-electrode assembly and a polymer electrolyte fuel cell, which utilize the water control sheet, are provided. The water control sheet is independent and located for use adjacent to a catalyst layer of a polymer electrolyte fuel cell, and is formed of a nonwoven fabric containing conductive fibers containing conductive particles at least inside a hydrophobic organic resin. The gas diffusion sheet, the membrane-electrode assembly and the polymer electrolyte fuel cell according to the present invention have the above water control sheet.