PURPOSE: To enable measurement of an indicator for sensitivity handily, by using a high frequency power and a high frequency magnetic field for applying a 180° pulse to a small receiving coil with a desired shape.

CONSTITUTION: An object to be inspected is inserted into a magnet 1, a transmitting/receiving coil 5 and an inclined magnetic field coil 9 to apply a magnetostatic field and an inclined magnetic field to an object to be inspected while a 180° RF pulse is applied properly to tilt a nuclear spinning in the object being inspected by 180° and a desired nuclear magnetic resonance signal S is received. Then, a measuring sequence is worked out in a computer 3 and sent to a sequence controller 2 as data. The device 2 encodes the data to output a signal necessary for a high frequency transmitter 4 and an inclined magnetic field power source 8 while sampling a signal S inputted through a coil 5 from the object being inspected. According to a modulation signal from the device 2, the transmitter 4 power amplifies an oscillator output oscillating at a resonance frequency after modulated to be sent to the coil 5 through an impedance matching device 12. On the other hand, the signal S is inputted into a high frequency receiver 7 through the matching device 12.