In a superconducting magnet, including a vacuum vessel, a coil vessel inside the vacuum vessel, and a superconducting coil inside the coil vessel for generating a magnetic field, has a magnetic member, disposed inside the vacuum vessel, supported with thermal insulation, for compensating the magnetic field a heat exchange device disposed outside the vacuum vessel for supplying to or absorbing heat from the vacuum vessel and thermal conducting members thermally connecting the heat exchange device via the vacuum vessel to the magnetic member. An MRI including the superconducting magnet is also disclosed.