Presently, the loose abrasive wire saw is the most commonly used technique for slicing hard and brittle materials. However its productivity is relatively low. A diamond wire saw has been developed for slicing brittle materials such as silicon wafer. The objects of this paper is to make the thin diamond wire saw apply to high cost production in semiconductor industries with the effective processing parameters such as machined surface roughness, material removal rate, the wear of the wire and the kerf width of the slicing. Effects of processing parameters on the performance of the diamond wire sawing processes are investigated by using the Taguchi method for this design of experiment (DOE). The analysis of the result shows that the optimal combinations for good surface roughness are small grain size, high wire speed, and low feed rate. Wire speed and feed rate are positively related to material removal rate.