Abstract: Disclosed is a rotor of a cryogenic electrical machine, comprising a superconducting field winding consisting of flat coils each of which is enclosed in a housing having therein tangential and axial passages, metal partitions disposed between the coils, an electrically insulating material, radial passages communicating the central cavity of the rotor with the tangential passages of the housing, and a bandage embracing the coils separated by said partitions, each housing being made up of a base embraced by the coil, wedges and inserts, radial passages being formed in the bases and wedges of the housings, and the electrically insulating material being made as strips forming passages communicating the radial passages of the bases and wedges.