To provide a method for manufacturing a stepped truss main material using an H section steel of a simple connecting structure which can surely position each member by a simple preparing work, facilitates a welding work, reduces a cost and shortens a construction period.

The method for manufacturing the stepped truss main material using the H section steel comprises the steps of: forming a V-shaped cutout part 3 on the stepped truss main material by assuring an interval corresponding to a thickness δ of a sandwiching plate 4 between one side piece flange plate 1A and a web plate 1C of a butt connected part 6 so as to manufacture the main material by butt connecting a substantially vertical member 1V and a substantially horizontal member H of an existing H section steel in a zigzag state; folding the other piece flange plate 1B via the plate 4 at the cutout part 3 so as to close the cutout part 3; and then connecting by welding the plates 1A, 1B and the plate 1C to the plate 4.