Abstract: The invention relates to a single contact spring, especially for RF-screening of electronic devices, for latch-locking into sheet-metal apertures. The invention envisages, in a first embodiment, that the single contact spring includes a latch cage (14) and a resilient contact part (2) configured as a contact cup (6), the latch cage (1) is generally configured in a trough shape and, in its lower part, trapezoidally in cross-section, being open at its two front ends and being provided on its two longitudinal sides with two opposing cutouts (16). The top edge of the longitudinal side is angled-off outward and the contact cup (6) is held by means of an angled-off, resilient carrier part (14) fastened to one of the front ends. The advantage of this spring is that it can be mounted in one mounting direction and can be laterally traversed. The contact cup can also, in a further embodiment, be configured in a roof shape.