1. A magnetic resonance imaging apparatus, comprising: an imaging unit that applies a high frequency magnetic field and a gradient magnetic field to an object placed in a static magnetic field and collects a plurality of echo signals by changing an echo time in one imaging; and a signal processing unit that creates a plurality of images having different echo times using a plurality of echo signals having different echo times, wherein the signal processing unit includes: a static magnetic field non-uniformity map creation section that creates a static magnetic field non-uniformity map, which shows phase rotation or frequency shift occurring in the plurality of images due to static magnetic field non-uniformity, using the plurality of images; a spatial direction discontinuity correction section that performs discontinuity correction processing, which is for correcting discontinuity of a phase or a frequency in a spatial direction, for a static magnetic field non-uniformity map acquired by the one imaging; and a time-series direction discontinuity correction section that performs discontinuity correction processing, which is for correcting discontinuity of a phase or a frequency in a time-series direction, for a plurality of static magnetic field non-uniformity maps acquired by time-series imaging, and a plurality of types of time-series images having different tissue contrasts are created using the plurality of images having different echo times and the static magnetic field non-uniformity map obtained by performing the discontinuity correction processing in the spatial direction and/or the time-series direction.