A magnetic resonance imaging apparatus having control unit for fetching a plurality of image data and obtaining an image by a calculation. The control unit performs an unwrap processing to a plurality of regions for removing a main value of a phase rotation amount so as to obtain a distribution diagram of a phase rotation amount caused by magnetostatic unevenness, obtains a plurality of evaluation values based on the phase value between a plurality of regions, selects a desired evaluation value based on the phase value from the plurality of evaluation values, and adjusts the phase values between the regions in accordance with the desired evaluation value.