PROBLEM TO BE SOLVED: To provide a superconducting magnet device including means for realizing stable permanent current conduction, which realizes open/close operation of a permanent current swith of the superconducting magnet device in a short time with a small electrothermal heater capacity, or to provide an MRI device using the same.SOLUTION: A superconducting magnet device has a superconducting coil and a permanent current swith, and realizes permanent current conduction by the permanent current swith operating by a thermoelectric heater. Alternatively, in an MRI device using the same, heat conduction path between the permanent current swith and a cooling stage is constituted of a heater consisting of an electrical resistor supplied with power from an external power supply and generating heat, so that it functions as a heat conduction member from the permanent current swith to the cooling stage at the time of cooling, and prevents cooling by having a higher temperature than the permanent current swith when the heater is generating heat.SELECTED DRAWING: Figure 1【課題】 本発明は、超電導磁石装置の永久電流スイッチの開、閉の動作を小さな電熱ヒータ容量で短時間に実現する安定な永久電流通電を実現する手段を備えた超電導磁石装置またはそれを用いたＭＲＩ装置を提供することを課題とする。【解決手段】超電導コイルと永久電流スイッチを有し、電熱ヒータで動作する永久電流スイッチにより永久電流通電を実現する超電導磁石装置、または、それを用いたＭＲＩ装置において、永久電流スイッチと冷却ステージの間の伝熱経路を外部電源からの給電により発熱する電気抵抗からなるヒータで構成することにより、冷却時は永久電流スイッチから冷却ステージへの伝熱部材として機能し、ヒータ発熱時は永久電流スイッチよりも高温となることで冷却を妨げる。【選択図】図１
