A safety switch for monitoring an access of an automation system includes a stationary part and a movable part. The safety switch has a first housing part having an elongate shape and a second housing part having a shape form-fitted with respect to the first housing part. The first housing part and the second housing part each have magnets. The first housing part is arranged in a fixed position in the stationary part of the access and the second housing part is arranged in the movable part of the access such that the magnetic elements are located opposite one another in a closed state of the access, the magnetic elements are magnetically effective together with one another, and a magnetic retaining force can be measured. The first housing part has a signal receiver and an evaluation unit and the second housing part has a signal transmitter, or vice versa.