PURPOSE: To minimize flame stabilizing air and prevent the increase of oxygen concentration in a furnace by a method wherein a flame stabilizing air pipe is provided around the outer periphery of a gas pipe while a high flow speed air passage, through which a part of the flame stabilizing air flows, is formed along the inner wall of the front part of the flame stabilizing air pipe.

CONSTITUTION: A part of flame stabilizing air, which flows through a flame stabilizing air pipe 2, increases the flow speed thereof simultaneously with entering a high flow speed air passage 4 by the affection of an air injection port 8 and the choking of the amount of air, then, is injected into a furnace with a high speed while cooling the fore part of the flame stabilizing air pipe 2 and an inside tubular body 6, which are exposed to a high temperature, and flowing along a flame stabilizer 5 at the tip end of a gas pipe 1. Accordingly, an area, becoming a high temperature especially, is cooled effectively by high- speed airflow since the high flow speed air passage 4 is provided at the vicinity of the flame stabilizer 5 while the inside tubular body 6 is constituted integrally with the flame stabilizer 5 whereby the flame stabilizer can be cooled effectively.