PURPOSE: To restrain an underfill from occurring and to manufacture a torsional extruded material having a prescribed lead by using a torsional extruding die having a torsion of a given lead, holding a billet actually at a given temperature and carrying out an indirect extrusion.

CONSTITUTION: Since the billet 24 is extruded actually while it is held in a given temperature, the extruding pressure is restrained from variation and, thus, no underfill arises on the torsional extruded material 2 obtained and, besides, the lead is restrained from variance. Further, indirect extrusion does not generate frictional force between the billet 24 and the inner wall of a container 20, accordingly, the extruding speed can be kept nearly at a constant from the start of the extrusion till the end thereof, as a result, an extruded material having a fixed lead is obtained.