There is provided a plastic working machine for plastically working a tube (33) by employing tube holding and spinning means for holding and spinning the plastically workable tube (33) around the axis of the tube (33) and first and second plastic working tools (57,58) which face to each other so as to pinch the tube (33) in the radial direction of the tube (33) and which are movable along the radial and axial directions of the tube (33) while being pressed against the tube (33). The plastic working machine executes a step of plastically working the tube (33) by the first and second plastic working tools (57,58) by continuously spinning the tube (33) around the axis thereof and by applying compressive load or tensile load along the axial direction of the tube to the tube (33).