A magnetic resonance imaging apparatus comprising: an RF coil, said RF coil comprising a whole body coil and a phased array coil; a pre-scan executing unit adapted to execute a pre-scan using a whole body coil and a pre-scan using a phased array coil prior to a main scan to generate three dimensional sensitivity map data; an image reconstruction unit adapted to generate a whole body coil reconstructed image and a phased array coil reconstructed image; a threshold value processing unit adapted to perform threshold value processing for both said whole body coil reconstructed image and said phased array coil reconstructed image, wherein, in said threshold value processing, regions where signal intensities are equal to or lower than a threshold are shown asa no-signal regions; a region reduction unit adapted to apply region reduction to a signal region near a no-signal region of image data obtained by the pre-scan, by replacing a section of said signal region near to no-signal region by a no-signal region after threshold processing for both said whole body coil reconstructed image and said phased array coil reconstructed image; a sensitivity map data generating unit that generates sensitivity map data using the image data after the region reduction; a smoothing processing unit that applies three-dimensional smoothing filter to the sensitivity map data; a main scan executing unit adapted to execute a main scan after the pre-scan; and an image data correcting unit adapted to slice the 3 dimensional sensitivity map and correct luminance of the image data acquired during the main scan using the sliced 3 dimensional sensitivity map data. an RF coil, said RF coil comprising a whole body coil and a phased array coil; a pre-scan executing unit adapted to execute a pre-scan using a whole body coil and a pre-scan using a phased array coil prior to a main scan to generate three dimensional sensitivity map data; an image reconstruction unit adapted to generate a whole body coil reconstructed image and a phased array coil reconstructed image; a threshold value processing unit adapted to perform threshold value processing for both said whole body coil reconstructed image and said phased array coil reconstructed image, wherein, in said threshold value processing, regions where signal intensities are equal to or lower than a threshold are shown asa no-signal regions; a region reduction unit adapted to apply region reduction to a signal region near a no-signal region of image data obtained by the pre-scan, by replacing a section of said signal region near to no-signal region by a no-signal region after threshold processing for both said whole body coil reconstructed image and said phased array coil reconstructed image; a sensitivity map data generating unit that generates sensitivity map data using the image data after the region reduction; a smoothing processing unit that applies three-dimensional smoothing filter to the sensitivity map data; a main scan executing unit adapted to execute a main scan after the pre-scan; and an image data correcting unit adapted to slice the 3 dimensional sensitivity map and correct luminance of the image data acquired during the main scan using the sliced 3 dimensional sensitivity map data.