This aims to shorten the time period, which is required for optimizing a radio-frequency magnetic field pulse intensity and thereby to shorten the measurement time period of an MRI entirety. In the operation for optimizing the radio-frequency magnetic field pulse intensity, an initial state for applying radio-frequency magnetic field pulses is intentionally created for a short time period and thereby to shorten the radio-frequency magnetic field pulse interval for the repeated applications. The radio-frequency magnetic field pulses are repeatedly applied at a predetermined time interval sufficiently shorter than the relaxing time period of the radio-frequency magnetic field pulses and the state in which the magnetic resonance signal intensity becomes a threshold value or less is set to an initial state.
