PURPOSE: To simplify manufacture with no winding work of a wire rod by applying conversion treatment to distinctly converting into an insulator to a plate-shaped superconductive member in order to spirally remain as untreated.

CONSTITUTION: A tube body 1 consisting of an oxide superconductive ceramic material, or a tube body 1 consisting of an insulating body coated with a superconductive film allover the peripheral surface is prepared. Next, the tube body 1 is made to rise or fall along the extending direction of the central axis while being made to rotate around the central axis thereof. At this time, a laser beam, X-rays are irradiated from an action source 2 converting a superconductive material into an insulating layer on the peripheral surface of the tube body 1 to generate a spiral insulating layer 3 for making the rest a superconductive part 4. Thereby, work of winding a wire is omitted, so that an excellent solenoid coil type superconductor can be obtained without lowering the strength of the magnetic field generated by a coil due to a fall of critical current density by the influence of a strain or the like at the time of winding the wire.