To provide a laser beam welding method capable of reducing defective welds by using a simple and efficient equipment and a method therefor when welding a work having a coated welding face.

Laser beam welding equipment transmits pulse laser beams produced by a pulse YAG laser beam oscillator to a predetermined portion of a work having a coated film formed thereon by an optical fiber via a machining nozzle, and the work is irradiated with laser beams and welded. The pulse waveform of the pulse laser beams is controlled by using the equipment. After the energy of the relatively small quantity is input for a predetermined time (the first pulse wave S1), the energy input is stopped for a predetermined time (the second pulse wave S2), and finally, the energy of the quantity higher than that of the first pulse wave is input to perform the welding (the third pulse wave S3).