To easily control a cut surface by providing a semiconductor ingot so as to make the same movable in its center axis direction and cutting the semiconductor ingot while controlling the displacement quantity of the ingot in the center axis direction corresponding to the change of the cutting position of the ingot.

In cutting a semiconductor ingot by a wire saw 1, the warpage tendency of the wire saw 1 is preliminarily analyzed by a surface detector because stable to obtain, for example, a warpage tendency value. This warpage tendency value is inputted to a displacement quantity control unit controlling the displacement of a work holding plate 21 in the center axis direction Y thereof and displacement quantity is applied to the work holding plate 21 corresponding to the change rate in the falling direction Z of a semiconductor wafer 3. Therefore, almost all of the preliminarily obtained warpage tendency value can be negated by the displacement quantity to cut a wafer having a flat cross section.