To provide a device and a method for removing an existing pile by securely separating and discharging the existing pile.

This device 1 for removing the existing pile is inserted in an annular space formed between the existing pile T buried in the ground and a casing 200 rotatingly press-fitted into the ground so as to surround the existing pile. The casing is chucked, and the device is rotated together with the casing to circumferentially form a cutout in the existing pile so as to cut out the vertical reinforcement thereof. Then the existing pile is cut off at the portion of the cutout, the separated existing piles are held, the casing is unchucked, and the existing piles are carried to the outside of the casing. The device comprises, from the upper side, a casing grip mechanism 2 gripping the inner surface of the casing from the outside to bring it in a chucked state, a pile chuck mechanism 3 holding the existing pile, and a pile cutter mechanism 4 having a cutter forming the cutout in the existing pile.