It is desired to perform assemble, disassemble, maintenance and the like, especially of a large site superconducting coil device, in a short time. The superconducting coil device includes a plurality of coil units arranged in a circle circumference to form a toroidal shape. Each of the plurality of coil units includes a cryostat and a superconducting coil stored in the cryostat, and has a first surface parallel with a radius of the circle circumference and a second surface parallel with the radius of the circle circumference and arranged in a first direction side of the circle circumference to the first surface. The first surface contacts with the second surface of a coil unit adjacent in one direction among the plurality of coil units. The second surface contacts with the first surface of a coil unit adjacent in other direction among the plurality of coil units.