An imaging apparatus includes an image sensor, a diaphragm control unit configured to control an aperture value of a diaphragm, and an electronic shutter control unit configured to control an operation of an electronic shutter for adjusting a charge accumulation time of the image sensor by adjusting a driving timing of the image sensor, wherein, if driving of the diaphragm overlaps a charge accumulation time when the aperture value is changed from a first aperture value to a second aperture value, the electronic shutter control unit controls a time of charge accumulation corresponding to the second aperture value in the charge accumulation time such that a brightness of an image signal output from the imaging unit when the first aperture value is set and a brightness of an image signal output from the imaging unit when the second aperture value is set become approximately equal to each other.