PROBLEM TO BE SOLVED: To provide a superconducting circuit capable of generating a stable static magnetic field at low cost.SOLUTION: A superconducting circuit includes: a first mode for switching a permanent current switch 12 from an on state to an off state so as to flow a current supplied from a superconducting coil power supply 14 into superconducting coils 11, 11； and a second mode for switching the permanent current switch 12 from an off state to an on state so as to flow a rated current into the superconducting coils 11, 11 with electrical connection between a second closed circuit K2 including the superconducting coils 11, 11 and a superconducting wire 12b and the superconducting coil power supply 14 being maintained.SELECTED DRAWING: Figure 1【課題】安定した静磁場を低コストで生成できる超伝導回路等を提供する。【解決手段】永久電流スイッチ１２をオン状態からオフ状態に切り替えて、超伝導コイル用電源１４から供給される電流を超伝導コイル１１，１１に流す第１モードと、永久電流スイッチ１２をオフ状態からオン状態に切り替え、さらに、超伝導コイル１１，１１及び超伝導線１２ｂを含む第２閉回路Ｋ２と超伝導コイル用電源１４との電気的接続を維持した状態で、超伝導コイル１１，１１に定格電流を流す第２モードと、を含む。【選択図】図１
