To provide a tip part structure of a pile with a rotary press-in type spiral blade allowing the spiral blade to smoothly bite into the ground while enlarging the side projecting dimension of the spiral blade to increase bearing power from the ground.

The tip side outer peripheral part of a pile body 6 is provided with the spiral blade 5 projected to the side, and the spiral blade 5 is provided in such a form that its outer peripheral position goes away outward in a radial line direction in a gradually enlarged manner toward the base end side from the tip side of the pile body 6. The tip part of the pile body 6 is provided with a tapered cone part 4b on the tip side of a straight part 4a, and the spiral blade 5 is provided in a range from the outer peripheral part region of the straight part 4a to the outer peripheral part region of the tapered cone part 4b. Further, the inclination in the spiral direction of the spiral blade 5 is gradually enlarged toward the base end side from the tip side of the pile body 6.