a superconducting cable is manufactured by providing spacers 12 in a plurality of cores 2 at the time of stranding of the cores 2 , and removing the spacers 12 before the stranded cores 2 are housed in a thermally insulated pipe and housing the cores into the thermally insulated pipe while the strands are held in a slacked state . by means of temporal interposition of the spacers , there is easily manufactured three cores having sufficient slack to manage thermal contraction which occurs when the cores are cooled in the thermally insulated pipe .