Laser welding method and laser welding device

A laser welding method, comprising:

• providing to a welding pattern selector a first welding pattern that causes an emission of shield gas through a laser nozzle provided on a laser processing head such that the shield gas is emitted at a mid-course position while moving the laser processing head along a travel path from a reference position to a starting position for welding the workpiece, the mid-course position being defined at a position intermediate the reference position and the starting position,
• the reference position being a stand-by position prior to moving the laser processing head along the travel path,
• the starting position for welding being a stand-still position at which the workpiece is welded,
• the first welding pattern causing an increase of the rate of the shield gas after starting the emission of the shield gas until the rate is stabilized,
• and, at the starting position for welding and when the rate of the shield gas is stabilized, starting radiating the laser beam onto the workpiece;
• providing to the welding pattern selector a second welding pattern that causes a start of emission of the shield gas when the laser processing head reaches the starting position for welding and radiating the laser beam onto the workpiece when the rate of the shield gas is stabilized;
• selecting and inputting a specific welding pattern into a welding pattern selector, the specific welding pattern being selected from among the first welding pattern and the second welding pattern;
• and
• performing laser welding on the workpiece according to the specific welding pattern that has been selected and inputted.