An optical tomographic imaging device and the like which suppress influence in the case of a measuring beam being truncated by an iris, and can ensure reliability of a tomographic image which is acquired, when imaging the tomographic image of a retina in an eyeground of an examined eye. An optical tomographic imaging device is configured to have an observation unit observing a state of irradiating an examined object with the measuring beam, and imaging a state of the measuring beam being incident on the examined object as an observation image, a recording unit recording the observation image by linking the observation image with a tomographic image by the optical tomographic imaging device, and an evaluating unit evaluating reliability of the tomographic image which is linked with the observation image based on the observation image imaged in the observation unit.