Abstract—Anisotropic materials represented by fiber-reinforced plastic (FRP) are widely used in various fields because of their high specific strength. However, the cutting resistance greatly fluctuates because anisotropic materials have strength anisotropy. Therefore, the field of cutting has been studied for a long time now. Meanwhile, several research reports on abrasive grain processing have been presented, but many unknown points exist at present. In this study, we investigated the generation mechanism of the sliced surface when slicing an anisotropic material using an electrodeposited diamond wire tool. Unidirectional glass fiber-reinforced plastic (GFRP) was used as the work material. Consequently, it was found that the slicing rate does not depend on the slicing angle or slicing area. The accuracy of the sliced surface roughness and the wafer thickness degraded as the slicing angle increased. The generation mechanism of the sliced surface differs depending on the slicing system. In other words, in the free abrasive grain system, it becomes the generation mechanism of the sliced surface mainly by microfractures. In contrast, in the fixed abrasive grain system, the generation mechanism of the sliced surface is mainly by microcutting in the ductility mode.