An imaging apparatus includes a tomographic image acquisition unit configured to acquire a tomographic image indicating a polarization state of a subject based on beams of different polarizations obtained by splitting a beam into which a return beam from the subject irradiated with a measuring beam and a reference beam corresponding to the measuring beam have been combined, and a control unit configured to control an optical path length difference between the return beam and the reference beam according to positional information of a predetermined region in the tomographic image indicating the polarization state of the subject.