Abstract: To improve the arc stability of a high-pressure arc discharge lamp, typically a xenon arc lamp, the cathode (4) has an essentially conical end portion (9), terminating in a roughly flat, or slightly rounded tip (10). The cathode is covered with a carbide layer (11) decreasing in thickness towards the tip (10) and, preferably, leaving a zone (12) adjacent the tip and extending over about one-third of the end zone (9) free from carbide. The carbide has a lower melting temperature than the tungsten of the electrode, and leaving the tip free from carbide prevents deterioration of the electrode due to melting of the carbide material, in operation of the lamp.