Abstract: The present invention relates to a method of operating an electrical discharge device (12) comprising at least one first electrode (14) and at least one second electrode (16) at a distance therefrom, which electrodes are electrically connected to a power supply (18) and, upon ignition of a first gas discharge (22) between the electrodes (14, 16), transmit an electrical current (1), as a result of which a plasma (24) is produced in a working gas (26), which plasma emits radiation (28), in particular extreme ultraviolet and/or soft X-ray radiation, which is passed via a solid angle (30) into a chamber (32) outside the electrodes (14, 16). In order to prevent erosion at the electrodes (14, 16), it is proposed that the formation of a secondary plasma (34) in the chamber (32) is suppressed by a device (42).