To provide a method of manufacturing a bellows tube which has excellent efficiency of heat exchange, which can be easily miniaturized and the productivity of which is high.

A bellows tube 10 is manufactured by a method having: a stage where a L-shaped strip material 13 having an L-shaped cross section is formed by bending a strip material along the center line 12 of the strip material 11; a stage where a helical material 16 is formed by winding the L-shaped strip material 13 in a spiral shape by taking the top part 14 of the L-shaped strip material 13 as the outside or the inside; and a stage where the adjacent edge parts 17 of the helical material 16 are joined. In this way, it is possible to continuously proceed with each stage starting from the strip materials having arbitrary dimensions and the bellows tube having an arbitrary length is manufactured. The productivity is improved because the inner diameter and outer diameter are freely set and the bellows tube having an arbitrary cross section is manufacturable because there are only a few conditions limiting the material size and the working size.