There is provided an optical tomographic imaging apparatus for imaging a tomographic image capable of setting characteristics of an optical system to accommodate to different positions on an object. The apparatus using an OCT system, includes: a scanning device for scanning measuring beams, an irradiating device for irradiating a different irradiation area on the object with the measuring beams scanned by the scanning device, an adjusting device for adjusting an irradiation position on the object of the measuring beams irradiated by the irradiating device, and a detecting device for detecting each combined beam produced from light interference between each of the return beams and the reference beams, characterized in that: the detecting device includes spectroscopy devices and a sensor, and a spectral width of the combined beam acquired with the sensor through the spectroscopy devices is set at a different spectral width by the spectroscopy devices.
