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