An optical coherence tomography (OCT) apparatus includes: a light source an OCT optical system including: a first light splitter which splits light emitted from the light source into measurement and reference lights, a second light splitter which splits the measurement light into first and second beams, an optical delay path to generate an optical path length difference between the first and second beams, a scan optical system which scans the respective beams on an object to be examined in a transverse direction, a reference optical system, and a detector which receives a spectrum of composite light in which reflected lights of the first and second beams from the object, and the reference light from the reference optical system are combined and an arithmetic controller which processes an interference signal output from the detector to obtain first and second tomographic images formed respectively by the first and second beams.