PURPOSE: To prevent the deviation of superconductive coils by injecting an impregnating material between the mutual superconductive coils.

CONSTITUTION: The impregnating material 8 such as water, oil, wax, etc. is injected into space between the internal coil 1 and the external coil 2 in the hybrid type superconductive magnet device consisting of both coils. The characteristics of the coils can be improved because the impregnating material 8 is solidified and the internal coil 1 and the external coil 2 are not moved by electromagnetic force by lowering the temperature of the superconductive magnet device. When the impregnating material returning to a liquid or a soft body at the normal temperature is used, the temperature of either of the internal and external coils 1, 2 is returned to the normal temperature and the impregnating material 8 is removed when either of the coils is degraded. Accordingly, the coils 1, 2 can easily be exchanged.