A welding method in an automatic welding machine in which welding is performed by impressing a voltage across a wire, which is transported along a welding path by a robot, and a workpiece to produce an arc at the tip of the wire, and transporting the wire tip along the welding path by the robot while the wire is successively laid out in small increments. The method includes storing a number of welding conditions in memory which conditions comprise welding voltage, wire feed speed, preflow duration, crater processing duration and postflow duration selecting prescribed welding conditions by the program, jetting a gas toward the workpiece for the preflow duration; thereafter generating a selected welding voltage and laying out the wire at a selected wire feed speed to start welding. The welding conditions are selected by the program at a welding starting point, and a predetermined welding voltage is generated for the crater processing duration, followed by performing crater processing by laying out the wire at a predetermined wire feed speed, and thereafter performing postflow processing by jetting gas toward the workpiece for the postflow duration; these welding conditions selected by the program at a welding end point.