PURPOSE: To obtain a fin tube having high joining strength and thermal conductivity by pulling up solidified part near molten metal surface on surface of a tube composing of material having higher melting point than that of this molten metal dipped in the molten metal together with the tube in order at the prescribed interval.

CONSTITUTION: After dipping the tube 2 into the molten metal 1 as remaining the upper end part having length B, cooling blast (for example, inert gas) is blown on the molten metal surface 15 from cooling nozzle 16. By this method, the molten metal surface 15 and neighborhood of the surface of the molten metal 11 are cooled to less than the melting point thereof in the range of depth W to form thin solidified layer 3a. The tube 2 is pulled upward by the distance corresponding to the prescribed fin pitch A and shifted upward under fixing condition of the solidified layer 3a to the tube 2 to part from the molten metal 11. By this method, one piece of the fin 3 is formed around the tube 2. Successively, by the same work as the above, the tube 2 is pulled up by the distance A, and a second fin 3 is formed. After that, by repeating the same work, the prescribed number of fins 3 is formed around the tube 2.