PURPOSE: To obtain a foundation pile well fixed to an excavated pit in a short time by a method in which rich-mixed cement milk is injected into an excavated pit with mud water, and a hollow pile is settled into the pit under its own weight.

CONSTITUTION: While the ground is excavated by a rotary rod auger 5 with stirring, pressure water is jetted from the tip of the auger 5 to form an excavated pit Ha with mud water in a place where a pile is to be buried. Rich-mixed milk C is injected into the bearing layer on the lower end of the pit Ha from tip of the auger 5 and the auger 5 is gradually pulled up to the ground's surface. A hollow pile 8 is settled into the pit Ha under its own weight, and the upper end of the pile 8 is fixed to the upper part of the pit Ha by a supporting steel plate 8b. The pile foundation which can be well fixed to the excavated pit can thus be constructed in a short time.