An imaging device comprising: an optical system that includes a first pupil that allows light within a first wavelength band to pass through, and a second pupil that allows light within a second wavelength band to pass through, the second wavelength band differing from the first wavelength band, and the first and second pupils (11, 13) being left and right pupils that are located in a plane perpendicular to the optical axis of the optical system and adjacent to each other; and an image sensor that includes a first-color filter that has first transmittance characteristics, a second-color filter that has second transmittance characteristics, and a third-color filter that has third transmittance characteristics, and configured to acquire a pixel value that corresponds to a first color, a pixel value that corresponds to a second color, and a pixel value that corresponds to a third color, wherein each pixel value is a product of the intensity of light incident on each pixel of the image sensor and the corresponding transmittance characteristic, characterized by a correction processing section configured to calculate the corrected pixel value that corresponds to the first color and the corrected pixel value that corresponds to the third color on the basis of a component value that corresponds to an overlapping region of the first transmittance characteristics and the third transmittance characteristics; and a phase difference detection section configured to detect a phase difference between an image formed by the corrected pixel value that corresponds to the first color and an image formed by the corrected pixel value that corresponds to the third color. an optical system that includes a first pupil that allows light within a first wavelength band to pass through, and a second pupil that allows light within a second wavelength band to pass through, the second wavelength band differing from the first wavelength band, and the first and second pupils (11, 13) being left and right pupils that are located in a plane perpendicular to the optical axis of the optical system and adjacent to each other; and an image sensor that includes a first-color filter that has first transmittance characteristics, a second-color filter that has second transmittance characteristics, and a third-color filter that has third transmittance characteristics, and configured to acquire a pixel value that corresponds to a first color, a pixel value that corresponds to a second color, and a pixel value that corresponds to a third color, wherein each pixel value is a product of the intensity of light incident on each pixel of the image sensor and the corresponding transmittance characteristic, characterized by a correction processing section configured to calculate the corrected pixel value that corresponds to the first color and the corrected pixel value that corresponds to the third color on the basis of a component value that corresponds to an overlapping region of the first transmittance characteristics and the third transmittance characteristics; and a phase difference detection section configured to detect a phase difference between an image formed by the corrected pixel value that corresponds to the first color and an image formed by the corrected pixel value that corresponds to the third color.