To maintain driving of a refrigerator even in a power interruption in a refrigerator cooling superconducting magnet apparatus having the refrigerator for cooling a superconducting coil on the power supplied from a power source.

The refrigerator cooling superconducting magnet apparatus includes the superconducting coil 18 which is energized by the power supplied from the power source 30, and a GM refrigerator 13 for cooling the coil 18 by the power supplied from the power source 30. When the power supply from the power source 30 is stopped, an electric connection of the refrigerator 13 to the power source 30 is disconnected, and a changeover switch 32 for electrically connecting the refrigerator 13 to the coil 18 is provided.