In a disposable diaper having a liquid-absorbent core which comprises, in turn, fluff pulp of less than 70% by weight and superabsorbent polymer particles of 30% or higher by weight, an isolating fibrous layer is placed on an upper surface of the liquid holding layer, then these liquid holding layer and isolating fibrous layer are integrally covered with a liquid-permeable covering layer such as a tissue paper, and these layers are intermittently bonded one to another over the entire extents of the respective laminating surfaces.