Abstract: A cutting apparatus for joint cutting system using robot includes a shaft combined with a motor in a part of a robot arm, a cutter having a cutting head at the end of the shaft, a sleeve in which the shaft is inserted, and a cutter support member having a sleeve base where the sleeve is fixed, characterized in that the sleeve is a standalone member of a hollow bar with a center hole and is separable from and combinable with the sleeve base. The sleeve and the sleeve base are so separable that it is possible to reinforce the strength of the sleeve, which retrains the bending force to the sleeve, though the diameter of the sleeve is minimized.