PROBLEM TO BE SOLVED: To provide a welding method that can more reliably ensure water-tightness while using pulsed irradiation of laser.SOLUTION: The welding method for forming, on an overlapping part of a first member 40 and a second member 50, a welded region 60 composed of a linear area formed by being irradiated with pulsed laser beams a plurality of times is characterized in that the welded region is formed such that a plurality of enclosed areas 64 surrounded by the linear area are annularly arrayed in series.【課題】レーザーのパルス照射を用いつつ、より確実に水密をとることができる溶接方法を提供する。【解決手段】パルス波レーザービームを複数回照射して形成された線状領域からなる溶接領域６０を第一部材４０と第二部材５０との重ね合わせ部に形成する溶接方法は、線状領域で囲まれた囲み部６４が、環状に連続するように複数並ぶことにより溶接領域が形成されることを特徴とする。【選択図】図４
