PURPOSE: To attain a dimensionally highly accurate cutting by a method wherein the slackness of a cutter blade at the slicing of a semiconductor ingot is removed by blasting air against multi-points and, at the same time, the planar positional change with the elapse of working time is detected so as to increase the depth of cut in response to the change.

CONSTITUTION: A blade 7 having an internal peripheral blade 7b is mounted to a chuck body 4 and rotatably supported by a main spindle 2 to a frame 1. In the frame, a plurality of supporting arms 12 having an air passage are provided radially so as to blast air from the air pads 121-124 provided at the tips of the supporting arms against the upper surface of the blade 7 so as to slice an ingot 8 with the internal peripheral blade 7b under a non-slacken state. On the other hand, with the elapse of working time, the slackness of the blade 7 increases, and the planar position of the blade changes from its initial position. The amount of the planar positional change is detected with position sensors S1-S4 and sent to controlling system, which controls a cutting-in shaft so as to increase the depth of cut in response to the changed amount.