To provide a vibration isolating tool for turning a thin-walled pipe which is capable of effectively suppressing the chattering vibration in turning a surface by being inserted in the thin-walled pipe to be turned, easy in attachment/detachment, and suitable for the turning by a robot line.

A cylindrical stock having the same outer diameter as the inner diameter of a thin-walled pipe P to be turned is cut in the axial direction with small cutting width so as to be split into a plurality of parts in the circumferential direction, cut parts 2a are butted to each other and combined with each other in a cylindrical condition, and split cylindrical vibration isolating bodies 2 in which a plurality of tightening grooves 3 are provided in the outer circumference with equal pitches in the longitudinal direction are integratedly tightened from the outer circumferential side by elastic tightening rings 4 fitted in each tightening groove 3 to form a vibration isolating tool 1. An outer circumferential surface of each vibration isolating body is closely attached to the inner surface of the thin-walled pipe by the centrifugal force caused by the rotation in the turning to suppress the chattering vibration, and when the pipe is stopped, the tool can be easily attached/detached by making the combined diameter of the vibration isolating body smaller than the inner diameter of the thin- walled pipe to be turned.