In this study, we developed a high transmission power stabilizer equipped with a Brewster window incorporating a proportional-integral-derivative (PID) controller. We used a 248 urn KrF excimer laser signals collected by a photodiode detector (PD) to stabilize the power fluctuation of pulsed laser in long-tenn drift situation. The power fluctuation averaged 2.73% after 45 minutes of uninterrupted operation. However, with the power stabilizer, the power fluctuation averaged 0.97%. The power stabilizer exhibited a maximum transmission rate of 96.9% which is better than that of conventional one and the maximum attenuated optical transmission reached 65.6%.