Low-pressure mercury lamp with specific electrode screens

A discharge vessel (10) encloses a discharge space (12) in a gastight manner, electrodes (21a, 21b) being arranged in the space and having a first (22a, 22b) and a second fastening (22a', 22b'). At least one of the electrodes (21a) is surrounded by a screen (23) which has a smallest width W, in a plane transverse to the tube axis (11) and transverse to the direction from the first (22a) to the second fastening (22a'), which width is smaller than the distance D between the fastenings (22a, 22a'). The screen (23a) has a length L in the direction of the tube axis (11) which lies between once and three times the smallest width W. The lamp consumes comparatively little mercury in the case of cold ignition.