To provide a grinding device for an ingot capable of suppressing the lowering of a grinding speed and shortening a grinding step time while especially enhancing machining distortion to the accuracy of 10 μm or smaller.

The grinding device for the ingot includes: a rough grinding wheel for rough grinding coaxially mounted to a single spindle; and a grinding means for performing traverse grinding by making a precise grinding wheel for precise grinding arranged at an inner side of the rough grinding wheel abut on an outer peripheral surface of the ingot. Cylindrical grinding is performed by performing precise grinding following the rough grinding by the grinding means while rotating the ingot. Alternatively, flat surface grinding is performed by performing precise grinding following the rough grinding by the grinding means without rotating the ingot held by the clamp. The grinding device for the ingot includes a moving means for moving forward and rearward the precise grinding wheel of the grinding means in an axial direction of the spindle. The precise grinding wheel is moved forward and rearward by the moving means and the wheel abutting on the ingot is selected to perform the grinding of the ingot.