To make it possible to continue stable bubbling in nonferrous refining by providing a blow-through pipe via the inside of the inner tube of a cylindrical water-cooled tube.

The pipe for bubbling comprises an iron blow-through pipe 1 and a stainless steel cylindrical water-cooled tube 2. The water cooling pipe 1 is formed in a jacket structure having outer, intermediate and inner tubes of concentrically annular section, and outer channel and inner channel are formed between the outer and intermediate tubes and between the intermediate and inner tubes. Cooling water introduced from a cooling water flow inlet 3 falls in the outer channel to arrive at the lowermost end, folded at the end of the intermediate tube, raised in the inner channel to arrive at the cooling water drain port 5. In the case of using, cooling water is introduced from a cooling water inlet 4, and drained from a cooling water drain port 5. The pipe for bubbling is installed in the hole provided at the ceiling of a furnace, the end of the pipe 1 is dipped in a melted material while blowing nitrogen as bubbling gas, and bubbling is conducted.