Disclosed is an imaging apparatus with a flicker detector that restrains an increased calculation amount and image quality degradation. The apparatus includes a frame rate controller for setting a frame rate of an acquired image to a first frame rate or different second frame rate, a luminance calculator for calculating a first luminance difference between two images of a first group continuously acquired at the first frame rate and a second luminance difference between two images of a second group continuously acquired at the second frame rate, and a flicker detector for comparing the first and second luminance differences with first and second threshold, respectively, and determining whether flickers of a first frequency and a different second frequency are generated or not.