With an MRI apparatus using a transmission coil having multiple channels, a region desired to be diagnosed is efficiently imaged with high image quality. The MRI apparatus comprises a region setting means for setting a region in an imaging region, of which high quality image is desired to be obtained, as a first region, and an optimization means for determining at least one of amplitude and phase of a radio frequency wave transmitted to each of the multiple channels as a radio frequency magnetic field condition, and the optimization means determines the radio frequency magnetic field condition so that at least one of specific absorption ratio and signal value of a region that generates artifacts is not higher than a predetermined value defined for each, under a uniformity constraint condition that uniformity of radio frequency magnetic field distribution in the first region is not lower than a predetermined value.
