PROBLEM TO BE SOLVED: To improve the productivity of a hot-water bag by improving the production efficiency of a lid and an opening, and reducing production costs.SOLUTION: A hot-water bag 1 comprises: a hollowed metallic hot-water bag body 2 a generally cylindrical opening body 3 that is attached to an opening 22d bored in an upper hot-water bag body 2 comprising the hot-water bag body 2 and thereby makes a water inlet and outlet 31 and a lid 5 that is attached to the opening body 3 detachably and thereby closes the water inlet and outlet 31. The opening body 3 is made of synthetic resin.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2016,JPO&INPIT【課題】本発明は、蓋体や口体の生産効率を向上させ、生産コストを低減させることで、湯たんぽの生産性を向上させることを目的とする。【解決手段】本発明の湯たんぽ1を、内部中空状に形成した金属製の湯たんぽ本体2と、該湯たんぽ本体2を構成する上側湯たんぽ本体2に形成した開口部22dに装着して給排水口31を構成する略筒状の口体3と、該口体3に着脱自在に装着して前記給排水口31を閉口する蓋体5とで構成し、前記口体3を合成樹脂で構成した。【選択図】図1