An intermediate layer is disposed between respective gas diffusing layers and catalyst layers of a polymer electrolyte fuel cell. This intermediate layer is mainly an electron-conductive filler and a binder, and has voids that are continuous in a thickness direction inside the intermediate layer, the intermediate layer has a solid volume percentage that is at least 3 percent and no larger than 30 percent, and a volume ratio occupied by voids that have a void diameter that is at least 1 μm and no larger than 30 μm of at least 50 percent of overall intermediate layer volume.