PURPOSE: To fix the direction of slicing surface with respect to the face direction of an ingot and contrive to reduce the cost of slicing operation by a method wherein a laser beam source, the position of which can be angularly adjusted and fixed so as to irradiate laser beams nearly normal to the end face of the ingot, is provided in a slicing apparatus main body.

CONSTITUTION: The small piece 6 of mirror-finished flat plate is sucked through water to the end face of an ingot, the slicing operation of wafer from which has been finished. The direction of a laser beam source 5 is adjusted and fixed so that the reflected beam of laser beam emitted from the laser beam source 5 to the direction indicated with the arrow returns to the slit of the laser beam source 5. After that, the ingot, the slicing operation of which has been finished, is removed and an ingot, the face direction of the end face of which is measured in advance, is mounted to an ingot holder 2 and the small piece 6 is sucked to the end face of the newly mounted ingot so as to emit laser beams in order to adjust the direction of the ingot so that the reflected beam returns to the slit of the laser beam source 5. Under the condition as just mentioned above, the ingot is sliced parallel to its end face. Accordingly, by adjusting the angle of the ingot on the basis of the face direction, which is measured in advance, of the end face of the ingot and the required Off angle, which is required to wafer, the slicing operation is performed.