Abstract: A welding method includes: layering two or more plate materials each including a plating plate material having a preform on a surface of which a plating layer is formed to form a workpiece; disposing the workpiece in a region to be irradiated with a processing laser beam; generating the processing laser beam having a power distribution shape in which two or more power regions are disposed along a predetermined direction in a plane perpendicular to a light traveling direction; irradiating a surface of the workpiece with the processing laser beam; and moving the processing laser beam and the workpiece relatively while performing the irradiation, and melting an irradiated area of the workpiece to perform welding while sweeping the processing laser beam in the predetermined direction on the workpiece during a swing of the processing laser beam.