An optical tomographic device comprising: a light source configured to periodically scan a wavelength of light; a measurement optical system (24, 72, 48) configured to irradiate light from the light source into an inside of a subject and guide reflected light from the inside of the subject; a reference optical system (24, 22) configured to guide the light from the light source as reference light; a calibration optical system (24, 72, 74) configured to irradiate a first calibration reflecting surface and a second calibration reflecting surface with light from the light source branched from the measurement optical system (24, 72, 48) or the reference optical system (24, 22), and guide the reflected light reflected by the first and second calibration reflecting surfaces (74a, 74b); a light-receiving element configured to receive the interfering light for measurement of the reflected light guided by the measurement optical system (24, 72, 48) and the reference light guided by the reference optical system (24, 22), and the interfering light for calibration of the reflected light guided by the calibration optical system (24, 72, 74) and the reference light guided by the reference optical system (24, 22); wherein the interfering light for calibration is obtained by using the first and second calibration reflecting surfaces (74a, 74b); characterized by an arithmetic logic unit configured to correct the interfering light for measurement received by the light-receiving element by using an analysis result obtained from the interfering light for calibration received by the light-receiving element, thereby correcting a nonlinearity of wavelength sweeping of the light source, and configured to correct an eye axial length or a plurality of one-dimensional tomograms in a two-dimensional tomogram or a three-dimensional tomogram calculated by using the corrected interfering light for measurement. a light source configured to periodically scan a wavelength of light; a measurement optical system (24, 72, 48) configured to irradiate light from the light source into an inside of a subject and guide reflected light from the inside of the subject; a reference optical system (24, 22) configured to guide the light from the light source as reference light; a calibration optical system (24, 72, 74) configured to irradiate a first calibration reflecting surface and a second calibration reflecting surface with light from the light source branched from the measurement optical system (24, 72, 48) or the reference optical system (24, 22), and guide the reflected light reflected by the first and second calibration reflecting surfaces (74a, 74b); a light-receiving element configured to receive the interfering light for measurement of the reflected light guided by the measurement optical system (24, 72, 48) and the reference light guided by the reference optical system (24, 22), and the interfering light for calibration of the reflected light guided by the calibration optical system (24, 72, 74) and the reference light guided by the reference optical system (24, 22); wherein the interfering light for calibration is obtained by using the first and second calibration reflecting surfaces (74a, 74b); characterized by an arithmetic logic unit configured to correct the interfering light for measurement received by the light-receiving element by using an analysis result obtained from the interfering light for calibration received by the light-receiving element, thereby correcting a nonlinearity of wavelength sweeping of the light source, and configured to correct an eye axial length or a plurality of one-dimensional tomograms in a two-dimensional tomogram or a three-dimensional tomogram calculated by using the corrected interfering light for measurement.