A technique for improving accuracy of temperature measurement in a living body using MRS/MRSI is provided. A cerebrospinal fluid suppression sequence that does not affect nuclear magnetic resonance signals of metabolite, but suppresses nuclear magnetic resonance signals of cerebrospinal fluid is executed in advance of execution of a signal measurement sequence for measuring nuclear magnetic resonance signals of water and a desired metabolite. There are thereby obtained spectra of water and the metabolite obtained from the nuclear magnetic resonance signals of water and the metabolite in which nuclear magnetic resonance signals of cerebrospinal fluid is suppressed. The obtained spectral peaks are fitted to a model function to obtain resonant frequencies of water and the metabolite, and the difference thereof is used to calculate temperature.