WELDING DEVICE AND WELDING METHOD

A welding device includes a laser irradiation unit that irradiates a workpiece with a laser light while scanning along an intended weld line of the workpiece, an upper jig arranged on a side of the laser irradiation unit with respect to the workpiece, and a lower jig arranged on an opposite side of the laser irradiation unit side. The upper jig includes an exposed portion that exposes the intended weld line of the workpiece to the laser irradiation unit side, an introduction path that is disposed in a downstream side in a scanning direction of the laser light and introduces an inert gas to the exposed portion, and a discharge path that is disposed in an upstream side in the scanning direction of the laser light and suctions the inert gas introduced to the exposed portion to discharge the inert gas to an outside.