PURPOSE: To offer the measuring method which can measure quantitatively an NMR spectrum of a desired specific part in a measuring object.

CONSTITUTION: In a position being symmetrical to a specific part in a measuring object centering around a surface coil 2 to which a holding block 16 is attached, a supporting tube 17 in which a reference sample 18 enclosed in a glass ball is stored is placed by inserting it into a hole of the holding block 16, and an NMR spectrum of the specific part is obtained by applying a magnetic field gradient with regard to the respective directions of X, Y and Z. Also, by inverting the polarity of the magnetic field gradient, taking the NMR spectrum of a reference sample and comparing it with the NMR spectrum of the specific part, the nuclide of the specific part can be measured quantitatively.