To propose an identification information creation apparatus offering improved reliability. This invention provides: an imaging means for imaging a unique in vivo imaging target existing inside a body; an optimization means for adjusting the imaging condition of the imaging means to be optimal for the in vivo imaging target and/or applying an image process so that the image condition of an image taken by the imaging means becomes optimal; and an identification information creation means for creating a first parameter which is set in the imaging means as a result of the adjustment by the optimization means and/or a second parameter which is obtained as a result of applying the image process by the optimization means, as identification information to identify the body.