An imaging device includes an illuminating unit configured to illuminate a measurement object with light from a light source an aberration correcting unit configured to correct aberration of the measurement object occurring in light returning from the measurement object, the returning light being provided by light illuminating the measurement object through an area differing from a center axis of the illuminating unit and an image obtaining unit configured to obtain an image of the measurement object on the basis of light returning from the measurement object, the returning light being provided by light that is provided after the aberration is corrected by the aberration correcting unit and that illuminates the measurement object through the center axis of the illuminating unit.