The influence of F2vibrational excitation and direct dissociation by electron impact is examined for conditions typical of electron‐beam‐sustained KrF* lasers. For values of F2fractional concentration greater than about 0.003 the results of this analysis indicate that the dissociation processe+F2→2F+emay significantly affect electron‐metastable atom production efficiency, rare gas–halide excimer production efficiency, and gain.