PURPOSE: To make the regulation of a shim coil current suitable for an analytical purpose of every kind possible by regulating the shim current so that the noticeable peak of a resonance spectrum becomes the shape suitable for the analytical purpose on the basis of the actually measured value of the noticeable peak.

CONSTITUTION: The resonance spectrum data of a sample is collected and four kinds of predetermined index values are calculated with respect to the resonance line indicated from the obtained spectrum data. Next, weighting is applied to the index values to obtain a synthetic evaluation value. Supposing that an objective value is set to the synthetic evaluation value, there are a system confirming whether a calculated evaluation value is within the objective value and a system confirming whether the difference between the current evaluation value and the previous evaluation value is within the objective value on the basis of the magnitude relation with the previous synthetic evaluation value but any evaluation system is arbitrarily used and one evaluation system is selected from a plurality of the evaluation systems. Finally, the control of a shim coil current is performed on the basis of the result of this synthetic evaluation to judge that the shim coil current finally reaches an object and the regulation of the shim coil current is completed.