In order to change a size of an imaging area of a tomographic image of an object to be inspected easily, provided is an optical tomographic apparatus for acquiring a tomographic image of an object to be inspected, the optical tomographic apparatus including a control unit for controlling a measuring light path length changing unit to change an optical path length of measuring light in a case where the size of the imaging area of the tomographic image is changed, and for controlling a reference light path length changing unit to change an optical path length of reference light in association with the change in the optical path length of the measuring light.
