A grinding apparatus includes grinding wheel side vibrational displacement calculation devices that obtain a vibrational displacement of a grinding wheel resulting from a vibration in an approaching/separating direction of the grinding wheel; main spindle side vibrational displacement calculation devices that obtain a vibrational displacement of a workpiece generated by propagation of the vibration in the approaching/separating direction of the grinding wheel; a relative vibrational displacement calculation unit that obtains a relative vibrational displacement between the grinding wheel and the workpiece based on the vibrational displacement of the grinding wheel and the vibrational displacement of the workpiece that have been obtained; a position change unit that creates, based on the obtained relative vibrational displacement between the grinding wheel and the workpiece, a position change command to change a position of the wheel spindle stock; and a processing controller that grinds the workpiece W based on the created position change command.