An imaging device of the present invention comprises an image sensor having a plurality of pixels made up of a first pixel group and a second pixel group, a flicker detection section for detecting bright states and dark states of all taken images based on a periodic flicker action of a light source contained in a subject from image output from the second pixel group, and a flicker correction calculation section 4 for, when light of brightness having bright states and dark states due to periodic flicker is incident, correcting brightness output gain corresponding to all pixels of the plurality of pixels corresponding to the first pixel group so that brightness output of taking images from the first pixel group becomes a standard brightness output.