To positionally stabilize the arc spot in a super-high pressure discharge
lamp which is filled with at least 0.20 mg/mm.sup.3 of mercury and to
prevent the formation of so-called flicker, in an operation device having
a high pressure discharge lamp and a feed device, the feed device of the
high pressure discharge lamp supplies a frequency in the range from 60 Hz
to 1000 Hz as the stationary operating frequency and a low frequency, in
a frequency range of from 5 Hz to 200 Hz is inserted which has an
inserted length of from one half period to five periods, and an inserting
period of from 0.01 seconds to 120 seconds, into the alternating current
of the stationary operating frequency. Furthermore, the parameters of the
low frequency are changed according to changes of the operating voltage
of the discharge lamp.