Provided is an imaging apparatus for acquiring a tomographic image of an object to be inspected based on light obtained by combining return light from the object illuminated with measuring light and reference light corresponding to the measuring light, the imaging apparatus including: a reference-light amount changing unit provided in an optical path of the reference light, for changing a reference-light amount of the reference light and a control unit for controlling the reference-light amount changing means so as to control the reference-light amount within a predetermined range and an image quality of the tomographic image within a predetermined image-quality evaluation range.
