LASER CUTTING METHOD

The laser cutting method for cutting a pair of plate materials, each of which has a different thickness and melting point, by irradiating them with a laser is provided with a plate material placement process for placing the pair of plate materials side by side so that, out of the pair of plate materials, an opposite surface of a laser irradiated surface of a plate material with a lower melting point protrudes more than an opposite surface of a laser irradiated surface of a plate material with a higher melting point, a focus adjustment process for aligning a focus position of the laser with an undersurface opposite the laser irradiated surface of the plate material with a higher melting point out of the pair of plate materials, and a plate material cutting process for cutting the pair of plate materials through irradiation with the laser according to a series of operations while sustaining a focus position of the laser to the pair of plate materials.