An electrical bushing (1) for connecting a superconducting device to a device located at ambient temperature, the bushing (1) having an electrical conductor (9) and an insulating layer (10) surrounding the electrical conductor (9). An interlayer (15) is provided between the electrical conductor (9) and the insulating layer (10) and makes it possible for the electrical conductor (9) to slide in the insulating layer (10) within a temperature range of from 70 kelvin to the ambient temperature. A field control layer (11) is also applied to the insulating layer (10).