A magnetic resonance imaging apparatus which executes a scan for allowing an RF coil unit to transmit RF pulses to an imaging area of a subject in a static magnetic filed space and allowing the RF coil unit to acquire magnetic resonance signals generated in the imaging area, includes: a scan section which executes, as the scan, each of an actual scan for acquiring the magnetic resonance signals as actual scan data and a reference scan for acquiring the magnetic resonance signals as reference scan data; an image reconstruction unit which reconstructs an actual scan image about the imaging area, based on the actual scan data and reconstructs a reference scan image about the imaging area, based on the reference scan data; a transmission sensitivity distribution calculating unit which calculates a transmission sensitivity distribution at the transmission of the RF pulses by the RF coil unit in the imaging area, based on the reference scan image and the actual scan image; and an image correcting unit which corrects the actual scan image using the transmission sensitivity distribution, wherein the transmission sensitivity distribution calculating unit includes: a division image generating part which executes image processing for dividing the first reference image by the second reference image, thereby generating a division image; a labeling information generating part which executes a labeling process on the division image thereby to generate labeling information about the division image; a segmentation process executing part which executes a segmentation process on the actual scan image, based on the labeling information thereby to extract a plurality of segments from the actual scan image; and a fitting processing part which calculates relational expressions indicative of relationships between pixel values of pixels constituting the segments and pixel positions thereof with respect to the segments extracted from the actual scan image, by performing a process for fitting to polynomial models, and wherein the transmission sensitivity distribution is calculated based on the relational expressions calculated by the fitting processing part.