The problem of the operational stability of a KrF laser with an averag
e output power of at least 600 W was investigated. An experimental stu
dy was made of the dependences of the rms deviation sigma of the outpu
t energy on the charging voltage, on the pulse repetition rate, and on
the operating time. The value of sigma varied from 1.2% to 6.0%, depe
nding on the experimental conditions. For an average power of similar
to 600 W, the deviation a did not exceed 3.2%.