A laser welding apparatus that welds a butted interface of a workpiece by laser light irradiation while successively feeding the workpiece having the butted interface to a welding position includes an X- and Y-axis scanner that scans laser light outputted from a laser light source in an X-axis direction and a Y-axis direction which are orthogonal to each other, a measuring device that measures a dimension along the butted interface, and a scanner control device that controls driving of the X- and Y-axis scanner so as to weld the butted interface by laser light irradiation.