Provided is a technique that enables accurate SAR management using power consumption by an object (Pobject) that was calculated based on accurately acquired Q-factors. For this purpose, the present invention calculates Q-factors of each channel of a high-frequency antenna using measurement results of amplitudes of forward waves and reflected waves of each high-frequency signal between three or more different frequencies. An existing SAR monitor in an MRI apparatus is used for the amplitude measurement. Also, the Q-factors are calculated based on a circuit coefficient to be acquired by fitting the measurement results to a predetermined circuit model. Then, the power consumption by an object (Pobject) is calculated using the calculated Q-factors in order to manage the SAR.
