A 5 microsec e-beam pumped XeF laser is described. Low concentrations of xenon and fluorine donor (NF3 or F2) were required to reduce losses for long-pulse operation at low (27 kW/cc) pump rates. Better performance was obtained using NF3 as the fluorine donor. The intrinsic efficiency was found to be flat over the laser pulse length, and averaged 1.1 percent. The laser output consisted of only the 353 nm line. A Rigrod treatment yielded a net gain 0.5 percent/cm.