To provide an inspection method for metal piping in a structure sealing a pipe end part without using solder of a refrigerator to facilitate regenerative utilization of resources, in the method performing effectively leakage inspection of copper piping for heat radiation mounted in the refrigerator.

A roll-shaped wound copper pie 6 is sizing cut, an end part is diametrically spread, and a slit 7 is provided in both ends of the copper pipe 6. Successively in one end of the copper pipe 6, a labyrinth-shaped bending part 17 is provided, and the end part is sealed. Successively the copper pipe 6 is worked in shape of piping in a front surface part, to be mounted in a steel plate constituting a front surface of a refrigerator. Further, the end part without sealing the copper pipe 6 is welded to an end part of piping in a main body part, inside the piping is pressurized from its opening side, and leakage inspection is performed.