The present invention makes it possible to easily perceive the calculation precision of a calculated magnetic susceptibility calculated on the basis of an image acquired by an MRI device. In the present invention, a high-frequency magnetic field pulse and an inclined magnetic field are applied to a subject placed in a static magnetic field, and a nuclear magnetic resonance signal is detected as a complex signal from the subject. A subject image (31) is reconstructed from the complex signal. A magnetic susceptibility distribution (32) of a tissue of the subject is calculated on the basis of the subject image (31). A confidence distribution (33) indicating the calculation precision of the magnetic susceptibility is calculated on the basis of the subject image.
