A safety switch (1) having a reading head (2) and an actuator (3) having a transponder (4) and being movable relative to the reading head (2). Encoded signals of the transponder (4) are detectable by means of the reading head (2). As a means for detecting encoded signals, the reading head (2) has a resonant circuit (6) controlled by a processor unit, with the distance between the actuator (3) and reading head (2) being determined by means of an amplitude evaluation of the signals of the transponder (4) detected with the resonant circuit (6). Control signals are generated as a function of the distance signals thus determined.