A superconducting cable having improved transmission efficiency
facilitates the laying operation and reduces heat intrusion. The
superconducting cable comprises a first pipe 105 within which are
accommodated a refrigerant passage section 101, a superconducting member
102 and an electrical insulating section 103, and a second pipe 106
arranged on the outer side of the first pipe. A vacuum heat insulating
section 104 is provided between the first and second pipes. The second
pipe is formed of a ferromagnetic material.