A magnetic resonance imaging apparatus comprising: processing circuitry configured to: using a gradient echo pulse sequence to generate a plurality of phase images of a subject corresponding to a plurality of echo times using MR data with different echo times, wherein the MR data is collected using the gradient echo pulse sequence; a susceptibility map generation unit configured to generate a susceptibility map quantitatively indicating susceptibility in the subject by a non-linear processing of the phase values of the plurality of phase images; a conductive map generation unit configured to: generate a conductivity map quantitatively indicating conductivity in the subject by using the susceptibility map by transforming the susceptibility map in accordance with Maxwell's equation, convert for each pixel a respective susceptibility value to an inclination, a, of a regression line in accordance with the equation φ = a * TE + φ 0 where φ is the phase value of a phase image of the plurality of phase images, TE is echo time of the respective phase image and φ 0 is an initial phase value at a point when the echo time TE is zero, specify the initial phase value in a point when the echo time is zero, φ 0, by regression using the phase values and corresponding echo times of the respective phase images and the inclination, a, and calculate a conductivity value using the specified initial phase value and generate the conductivity map using the calculated conductivity value. processing circuitry configured to: using a gradient echo pulse sequence to generate a plurality of phase images of a subject corresponding to a plurality of echo times using MR data with different echo times, wherein the MR data is collected using the gradient echo pulse sequence; a susceptibility map generation unit configured to generate a susceptibility map quantitatively indicating susceptibility in the subject by a non-linear processing of the phase values of the plurality of phase images; a conductive map generation unit configured to: generate a conductivity map quantitatively indicating conductivity in the subject by using the susceptibility map by transforming the susceptibility map in accordance with Maxwell's equation, convert for each pixel a respective susceptibility value to an inclination, a, of a regression line in accordance with the equation φ = a * TE + φ 0 where φ is the phase value of a phase image of the plurality of phase images, TE is echo time of the respective phase image and φ 0 is an initial phase value at a point when the echo time TE is zero, specify the initial phase value in a point when the echo time is zero, φ 0, by regression using the phase values and corresponding echo times of the respective phase images and the inclination, a, and calculate a conductivity value using the specified initial phase value and generate the conductivity map using the calculated conductivity value. a susceptibility map generation unit configured to generate a susceptibility map quantitatively indicating susceptibility in the subject by a non-linear processing of the phase values of the plurality of phase images; a conductive map generation unit configured to: generate a conductivity map quantitatively indicating conductivity in the subject by using the susceptibility map by transforming the susceptibility map in accordance with Maxwell's equation, convert for each pixel a respective susceptibility value to an inclination, a, of a regression line in accordance with the equation φ = a * TE + φ 0 where φ is the phase value of a phase image of the plurality of phase images, TE is echo time of the respective phase image and φ 0 is an initial phase value at a point when the echo time TE is zero, specify the initial phase value in a point when the echo time is zero, φ 0, by regression using the phase values and corresponding echo times of the respective phase images and the inclination, a, and calculate a conductivity value using the specified initial phase value and generate the conductivity map using the calculated conductivity value. generate a conductivity map quantitatively indicating conductivity in the subject by using the susceptibility map by transforming the susceptibility map in accordance with Maxwell's equation, convert for each pixel a respective susceptibility value to an inclination, a, of a regression line in accordance with the equation φ = a * TE + φ 0 where φ is the phase value of a phase image of the plurality of phase images, TE is echo time of the respective phase image and φ 0 is an initial phase value at a point when the echo time TE is zero, specify the initial phase value in a point when the echo time is zero, φ 0, by regression using the phase values and corresponding echo times of the respective phase images and the inclination, a, and calculate a conductivity value using the specified initial phase value and generate the conductivity map using the calculated conductivity value.