A superconducting magnet configured for an NMR spectrometer includes a
split type superconducting magnet having left solenoid superconducting
magnets and right solenoid superconducting magnets with a center space
therebetween for receiving a sample tube. A permanent current switch is
provided and the left and right solenoid superconducting magnets are
arranged symmetrically with respect to a center face of the center space.
The left and right solenoid superconducting magnets are constituted by an
outermost magnet and a plurality of innermost magnets and are arranged in
concentric relation with respect to a vertical axis of the center space.
A direction of current in at least one of the plurality of innermost
magnets is minus when a direction of current in the outermost magnet is
plus.