PURPOSE: To improve anti-corrosive characteristic of a heat transfer pipe by a method wherein after the heat transfer pipe is inserted into a thermo-shrinkage resin tube it is formed into a coil shape, thereafter the thermo-shrinkage resin tube is heated and shrunk and coated on an outer circumferential surface of the heat transfer pipe.

CONSTITUTION: A full length of a straight copper pipe 2 is inserted into a thermo-shrinkage resin tube 3a. After this operation, the copper tube 2 inserted into the thermo-shrinkage resin tube 3a is formed into a coil shape. This is heated and the thermo-shrinkage resin tube 3a is shrink and closely coated on an outer circumferential surface of the copper tube 2. With such an arrangement as above, the thermo-shrinkage resin tube 3a coated at the outer circumferential surface of the copper tube 2 becomes a resin film 3 of the heat transfer pipe 1 to enable an anti-corrosion of the heat transfer pipe 1 to be improved. The thermo-shrinkage resin tube 3a is not damaged during forming operation.