To increase a diameter of a steel pipe pile, reinforce bearing force and to deepen the depth of laying.

A disc having a diameter at least larger than that of a pile body is concentrically mounted to the lower end of the steel pipe pile body, a triangular plate directed downward by fitting the top to a core of the pile body is mounted to the central part of the lower surface of the disc, at the same time, an excavating edge is mounted within a distance to the circumference of the disc on the extension of the triangular plate, and a spiral wing larger than the diameter of the disc is mounted on the circumference of the upward pile body of the disc.