Nuclear magnetic resonance spectrometer and method for its operation

There is provided while realizing a large uniformity of a static magnetic field and a high measurement sensitivity provided a nuclear magnetic resonance spectrometer with high sensitivity. A solvent used in the nuclear magnetic resonance spectrometer sample tube is constructed in a structure in which the shape of a placed in a measuring space sample can be changed. The change in shape of the sample can be achieved by controlling the pressure exerted on the sample. There is at least one contact surface between the placed in the measurement space sample and an existing around the sample gas and the shape of such a surface is maintained by the surface tension of the sample. In this case, a central portion of a magnet into which the sample tube is inserted, filled with a sterilizing gas having a pressure higher than the ambient pressure and the sample with a contact surface for gas is maintained in a sterile condition. A measuring coil used in the nuclear magnetic resonance spectrometer is mounted on a rotatable curved surface that is symmetrical with respect to an axis of rotation that is provided by a longitudinal central axis of the sample tube.