A magnetic resonance apparatus with a radio-frequency shield at a reference potential, a detuning circuit and an electrical line which is connected with the detuning circuit. The electrical line is fashioned as a strip conductor and is attached to the radio-frequency shield. The strip conductor can be used for direct current/direct voltage supply of the detuning circuit. This has the advantage that the detuning circuit can be activated without exerting a significant interfering influence on the magnetic field in the magnetic resonance apparatus.