To crush an existing pile by efficiently crushing and removing a joint part from the existing pile using an existing auger regardless of the magnitude of the wall thickness and diameter of the joint part.

A crushing arm 5 is fixed oscillatably on a horizontal shaft 3 on the side of a device main body. The crushing arm 5 is formed of a lower arm 6 having a crushing blade 17 on its lower end and an upper arm 12 connected to the upper and part of the lower arm 6 in a V-shape. A stopper 18 to restrict the oscillating direction of the crushing arm 5 is fixed so as to form a joint part crushing and removing device 20. The lower arm 6 with the crushing blade 17 is inserted into a hollow part 24 of an existing pile 23, the crushing and removing device 20 is pressed downward while being rotated, and the upper arm 12 is pressed against the upper end of the existing pile 23 (power point). By its repulsion, the crushing blade 17 is pressed against an inner wall 25 of the existing pile 23 (point of application) to from an annular groove (30) and separate a joint part. The separated joint part is locked to the crushing arm 5, and exhausted up to the ground.