The authors investigate a low-fluence laser processing system with a femtosecond double-pulse beam and surface excitation of a power semiconductor wafer. The double-pulse laser processing method enables a semiconductor surface to be processed at a lower fluence and prevents penetration damage of the processed surface. The first pulse of the double beam is considered to have a role in exciting the semiconductor surface to increase the efficiency of light energy absorption. In this report, to verify the feasibility of low-fluence processing, we measure the damage threshold in the low-fluence ablation process.