PURPOSE: To make up for a difficult point caused at a scribing method and a blade method which are executed to a dicing line formed on a semiconductor wafer composed of a III-V compound and to obtain a perfect chip without sharply increasing a chip size and by enhancing a material efficiency.

CONSTITUTION: At a semiconductor wafer composed of a III-V compound, dicing lines 4, 5 formed on the semiconductor wafer are diced in a direction perpendicular to an orientation flat at (011) by a scribing method after flaws have been formed and a force has been exerted, and the dicing lines which are parallel to the orientation flat at (011) are diced by a blade method. As a result, chippings are not produced and it is not required to form an excess space on the dicing lines 4, 5. Consequently, a material efficiency is increased, and the title method contributes extremely largely to the semiconductor wafer composed of the expensive III-V compound.