PURPOSE: To reduce a locating error due to linear expansion in a support member, by installing a measuring reference member, a detecting device detecting a linear expansion quantity and a controlling device controlling operations of a driving source all in a precisoin cutter which cuts a semiconductor wafer.

CONSTITUTION: A precision cutter is provided with a static main base 2, while a support device 4 on this main base 2 comprises a movable support base 6, a movable sub-support base 8 and a support member 10. A mounting bracket 90 is locked onto a bearing member 60 of this support member 10, and a measuring reference member 92 is supported on this mounting bracket 90 in a cantilever way. On the other hand, a projecting piece 94 is locked to a right edge of the support member 10, and a photodetector 96 detecting a detected line of the measuring reference member 92 is installed on this projecting piece 94. While the support member is expanded or contracted due to a variation in temperature, the measuring reference member 92 moves to the left or the right, whereby the photodetector 96 detects a linear expansion quantity in the support member 10. A signal out of this detector 96 is fed to a controlling device, compensating the locating movement of a cutting blade 68.