An adhesive layer is placed in a region outside an outer peripheral edge part of a second catalyst layer, on a second surface of an electrolyte membrane. A support frame is placed via the adhesive layer such that the second catalyst layer and a second gas diffusion layer are placed inside an opening of the support frame. A specific region as a region between the outer peripheral edge part of the second catalyst layer and an inner peripheral edge part of the opening of the support frame is present. A predetermined material is placed inside a recessed portion present on a surface of the adhesive layer inside the specific region, the predetermined material containing at least one of a first substance having an action of decomposing hydrogen peroxide and a second substance having an action of decomposing hydroxyl radicals.