PURPOSE: To provide the device affording a treatment environmental space in varying high magnetic field as a space bringing about the whole or part of specific effect on the production of a material, the cultivation of living things or remedy for the invalids.

CONSTITUTION: A refrigerant vessel 2 and coil cases 3 filled with a refrigerant are arranged in the peripheral wall part 1 of a device main body 1 so as to insert Helmholtz coil consisting of two each of coils comprising a superconductive magnet into the coil cases 3. A power supply is composed of two each of AC power supplies in 180° different phase to be respectively connected to respective coils. At this time, the circular cylindrical space in the device main body is used as the treatment environmental spaces 8. The power supply is composed of voltage current and a control means controlling the frequencies thereof if necessary.