PROBLEM TO BE SOLVED: To provide a method for manufacturing a heating instrument which can contribute to quality improvement by efficiently obtaining the required amount of a sheet material covering the heating instrument at a low cost and appropriately obtaining the heating instrument having desired heating characteristics, wherein both sides of the sheet material have different air permeability.SOLUTION: In a method for manufacturing a heating instrument 10 which includes a heating element 1 coated with an air-permeable sheet having openings, openings are continuously made in a long-length sheet raw material 41 by an opening means 43 and the air permeability of heating element opposing regions, which are parallel in at least width direction of the long-length sheet raw material 41, are made different from each other. The heating element opposing regions with different air permeability of the long-length sheet raw material 41 are arranged in both sides of the heating element 1, respectively. The long-length sheet raw materials, which are arranged in both sides of the heating element 1, are joined and the heating element 1 is enclosed.COPYRIGHT: (C)2013,JPO&INPIT【課題】発熱体を包被するシート材を両面で通気性の異なるものとする場合、その必要量を効率よく低廉に得て、所望の発熱特性を有する発熱具を適切に得て品質向上に資することができる発熱具の製造方法を提供する。【解決手段】開孔を有する通気性シートで被覆された発熱体1を備える発熱具10の製造方法であって、長尺状のシート原反41に開孔手段43により連続的に開孔を施して、前記シート原反41の少なくとも幅方向に並列する発熱体対向領域同士の通気性を異ならせ、該シート原反の異なる通気性の発熱体対向領域を、前記発熱体1の両面にそれぞれ配置し、発熱体1の両面に配置されたシート原反を接合して発熱体1を封入する発熱具10の製造方法。【選択図】図2
