A burst wave 91 is applied as an RF magnetic filed in order to excite nuclei of hydrogen, and also a oradient magnetic field 95 along a readout direction is applied so as to excite magnetization in a stripe shape. Thereafter, while a magnetization-inverting RF magnetic field pulse 92 for selecting a slice is applied and a readout gradient magnetic field 96 is applied, a signal 97 is measured. At this time, a time instant when a spin echo is produced is made different from a time instant when a gradient magnetic field echo is produced, so that a phase rotation made by a chemical shift may be reflected on to a signal. The MR signal 97 is processed by a 2-dimensional Fourier-transform, and a phase distribution is calculated from both a real part and an imaginary part of complex data after the 2-dimensional Fourier-transform. Then, this calculated phase distribution is converted into a temperature change so as to display the temperature change. A temperature change in a diseased portion in connection with IVMR can be monitored in real time.