PURPOSE: To make a high-inductance superconductive coil formable easily, by coating a surface of a cylindrical substrate with a superconductive material and sintering this material to form a superconductor layer and next by forming a spiral groove on this superconductor layer so deeply that the groove attains to said substrate.

CONSTITUTION: A surface of a cylindrical substrate 1 made of an insulating material is coated with a superconductive material, and this material is sintered to form a ceramic superconductor layer 2. Next this substrate is rotated and concurrently a cutter 4 is used to form a spiral groove 3 on the superconductor layer 2. Then said groove 3 should be so deep that it penetrates into the superconductor layer 2 and attains to the substrate 1. When spacing of said groove 3 is made small, the number of coil turns can be enlarged, so that the coil with large inductance can be formed easily without joints.