A magnetic bearing of a rotor shaft relative to a stator is described, which has the following features: (a) the rotor shaft (1) contains an arrangement of permanent-magnet elements (2) arranged side by side in the region of the stator (3); (b) the stator (3) has a structure (6a) with high-Tc superconductor material with grains; (c) the high-Tc superconductor material is located in/on the surface of a heat sink (6) that is arranged coaxially with the rotor shaft (1); (d) the heat sink (1) either has a cooling channel (8), which is also arranged coaxially with the rotor shaft (1), or is formed as a solid piece and is in contact with a cold head; and (e) the heat sink (6) is located inside an evacuated housing (5).