Abstract: In the method of scarfing surface defects of to-be-scarfed metal material as said material is moving relative to the scarfing machine with scarfing nozzle, the improvement, which comprises a step of supplying oxygen into the consumable electrode pipe so provided as to be directed to a scarfing point on the surface of said to-be-scarfed metal material, for jetting the oxygen from the tip of said electrode pipe, a step of feeding said electrode pipe until its tip contacts said metal material, a step of heating rapidly the contacting portion respectively of said electrode pipe and of said metal material with electrical energy and heat of oxidation so that the temperature of such portion may rise to scarfing start temperature, and a step of initiating the scarfing process instantaneously from such temperature rising portion with the oxygen jetted to said scarfing nozzle.