Abstract: The invention relates to a safety circuit (10) for use in an explosion-proof casing (12). The safety circuit (10) is disposed for discharging a capacitor arrangement comprising at least one capacitor (19) that is associated with an electrical operating means (11). The at least one capacitor (19) is discharged, in a defined manner, via the safety circuit (10) through an electrical discharge circuit (33) during a discharge time period (ET), after a supply voltage (UV) on a power supply input (13) is switched off. At the end of the discharge time duration (ET), the electrical charge or the electrical energy of the at least one capacitor (19) is sufficiently low, so that an ignition of the potentially explosive atmosphere in the environment of the explosion-proof casing (12) is precluded.