1. An optical coherence tomography method that divides light from a light source into measurement light and reference light and acquires a tomographic image of an object based on a wavelength spectrum of interfering light of the reference light and return light, the return light returning from the object upon irradiating the measurement light onto the object, the optical coherence tomography method comprising the steps of: acquiring a measurement image based on the wavelength spectrum at each of a plurality of measurement regions of the object adjacent to one another in a direction of irradiation of the measurement light; and acquiring a tomographic image at each of the plurality of measurement regions by removing a mirror image of a tomographic image of an adjacent region being adjacent to the measurement region from the measurement image.