The present invention relates to an armature spring (4) for a relay comprising a fastening section (3), a connected oblong spring section and a lever (7). The lever is located on the side of the longitudinal axis of the spring section opposite to that of the fastening section (3) so that the spring section is subject to torsional stress. Due to the torsional stress of the spring section, an even progression of the spring characteristic curve can be achieved. The stress is very even, so that the spring is very small and simple. In advantageous embodiments, the spring section extends parallel to the armature pivot axis and is formed by a torsion web (6). The lever section can be flexibly deformable. As a result the spring characteristic can be particularly easily and flexibly adjusted. As a result the spring armature can be combined with a magnet system exhibiting opening angles of 10° to 15°.