Excitation of atomic krypton in the presence of molecular fluorine by a wavelength‐selective 2.5‐ns‐long argon excimer photolytic source was used to initiate the reaction sequence resulting in the formation of excited KrF. The radiative lifetime of the KrF* laser transition was found to be 9 ns at the high‐pressure limit. This is in good agreement with the calculated values. The rate constant for two‐body quenching of KrF* by F2is 5.7±0.5×10−10cm3 s−1and the rate constant for three‐body quenching by Kr is 2.9±0.3×10−31cm3 s−1.