A welding apparatus according to one embodiment includes an irradiation device and nozzle. The irradiation device irradiates a surface of an object with an energy beam. The nozzle is provided with a first channel through which a shield gas flows and a second channel apart from the first channel and through which a gas flows, and the nozzle moves in an irradiation direction. The nozzle includes an end facing the surface and an outer face connected to the end and located in the irradiation direction with respect to the first channel. The end is provided with a first opening that communicates with the first channel and allows discharge of the shield gas toward the surface. The outer face is provided with a second opening that communicates with the second channel and allows the gas to be discharged away from the outer face in the irradiation direction.