Abstract: An NMR probe has a sample tube insertion port for introducing and withdrawing the sample tube into and from the probe, a sample tube support providing support of the sample tube during NMR measurements, a tubular sample tube passage connecting together the sample tube insertion port and the sample tube support and capable of transporting the sample tube between them, and a gas stream generator for producing a gas stream in the sample tube passage to move the sample tube between the sample tube insertion port and the tube support. The gas stream generator is mounted at an intermediate (non-end) position in the sample tube passage.

Abstract: An NMR spectrometer and method in the following three steps are performed. (1) An external magnetic field is set to H0+?H (where 4H>0). When the detection coil made of the superconducting material is still in a normal state, a magnetic field stronger than the ultimate target static magnetic field strength H0 by ?H is applied to the detection coil. (2) The detection coil made of the superconducting material is cooled down to T0 lower than its critical temperature Tc to bring the coil into a superconducting state while the external magnetic field H0+?H is applied to the detection coil. (3) The external magnetic field is lowered from H0+?H to H0 such that the applied external magnetic field is decreased by ?H while the detection coil is kept in the superconducting state.