1. A magnetic resonance imaging device comprising: a static magnetic field generator to apply a static magnetic field to a subject; a gradient magnetic field generator to apply a gradient magnetic field to the subject; a high frequency magnetic field pulse generator to irradiate the subject with a high frequency magnetic field pulse; a receiver to receive a nuclear magnetic resonance signal from the subject; and a computer programmed to control the gradient magnetic field and the high frequency magnetic field pulse, wherein the computer is further programmed to: detect the nuclear magnetic resonance signal generated from the subject as a complex signal by applying the high frequency magnetic field pulse and the gradient magnetic field to the subject placed in the static magnetic field, reconstruct a complex image, in which each pixel value of the complex image is a complex number, from the complex signal, convert the complex image into a magnetic susceptibility image by creating an absolute value image and a phase image from the complex image, create a processed magnetic susceptibility image from the phase image including: a step for calculating a low frequency region magnetic susceptibility image for a low frequency region of a k-space of the phase image; a step for calculating an edge information magnetic susceptibility image indicating an edge of a tissue in a magnetic susceptibility distribution, a step for calculating a high frequency region susceptibility image for a high frequency region of the k-space; a step for calculating an edge mask of a tissue from the edge information magnetic susceptibility image; a step for smoothing magnetic susceptibility values in a magic angle region of the k-space using the edge mask and the low frequency region magnetic susceptibility image; and a step for replacing magnetic susceptibility values in the high frequency region of the k-space using the high frequency region susceptibility image, and display the low frequency region, the smoothed magic angle region and the replaced high frequency region as the processed magnetic susceptibility image on a display.