GRINDING APPARATUS AND GRINDING METHOD

PURPOSE: A grinding device and a grinding method are provided to prevent the occurrence of cracks based on the cross section of a grinding object. CONSTITUTION: A grinding device comprises an upper plate, a lower plate, a sun gear, an internal gear, and a planetary carrier(5). The lower plate is located on the opposite side of the upper plate, and rotates to the reverse direction of the upper plate. The sun gear and the internal gear rotate to the same rotary axis the upper plate and the lower plate. The planetary carrier is installed between the upper plate and the lower plate, and comprises a cutaway part or clearances(11a, 11b) in a support hole(10). [Reference numerals] (11a,11b) Clearance;