The present invention provides a high-pressure discharge lamp that uses
substantially no mercury and reduces discharge flicker. The high-pressure
discharge lamp is kept on with a lamp power of 50 W or lower in a stable
state, and the temperature T (.degree. C.) of the electrode at a point at
a distance of 0.3 mm from the tip end to the base end in the stable state
and the amount A (mol/cc) of free iodine produced when the lamp is turned
off after 100 hours of on-time satisfy the formula
(1):T.sup.2/A>10.sup.11.