A superconducting magnet device configured for an NMR spectrometer includes a split type superconducting magnet having left and right solenoid superconducting magnets, wherein the split type superconducting magnet has a center space around a vertical center axis between the left and right solenoid superconducting magnets, a sample tube placed in the center space in order to enable placement of a sample therein, which is energized by the magnetic field generated by the split type superconducting magnet, a solenoid coil configured for detecting signals due to magnetic resonance from the energized sample, and a permanent current switch for holding the split type superconducting magnet to a permanent current mode.