PROBLEM TO BE SOLVED: To provide an OCT capable of acquiring information of a deep site of an object without requiring a high-speed and expensive AD conversion mechanism.SOLUTION: An optical interference tomography device has: a light source section changing the wavelength of emitted light an interference optical system splitting light from the light source section into irradiation light for irradiating an object and reference light, and generating interference light of reflected light obtained by irradiating the object and the reference light an optical detection section receiving the interference light a clock generation section, based on the light emitted from the light source section, generating a plurality of clock signals that have different phases from each other and have the same wave number interval with each other and an information acquisition section acquiring a plurality of interference signals on the same position on the object, sampling each of the plurality of interference signals on the basis of the plurality of clock signals, and acquiring information of the object on the basis of the sampled interference signals.
