We have developed a comprehensive computer code to analyze output performance of KrF laser excited by an intense electron beam. Especially for short pulse (<100 ns) and high excitation rate (≳1 MW/cm3) pumping, and under realizable conditions, we have calculated the intrinsic laser efficiency as a function of excitation rate. The results were compared with some experimental results which have been already reported by other groups, and a fairly good agreement was obtained. At an excitation rate of 1.5–2 MW/cm3, and at a total gas pressure of near 1.5–2 atm, an intrinsic efficiency of up to 11.5% is found to be attainable. At 3–4 atm, even at an excitation rate of near 7 MW/cm3, the efficiency of 9% is obtainable. We have also calculated the KrF* production efficiency and the laser extraction efficiency, and explained the output performance in terms of excitation rate.