1. An image verification device that checks an input image obtained by photographing an object to be checked against a registered image database, wherein, in the registered image database, an amount of feature of an image obtained by photographing an object is registered as a registered image, and the registered image includes registered images registered with respect to a plurality of objects, wherein the image verification device comprises: a verification score calculating unit that calculates a verification score serving as a score representing a degree of approximation between the objects indicated by the registered images and the object of the input image by using the amount of feature of the input image and the amounts of feature of the registered images; a relative evaluation score calculating unit that calculates a relative evaluation score serving as a score representing a degree of approximation between one object registered in the registered image database and the object of the input image in comparison with the other objects; an integrated score calculating unit that calculates an integrated score obtained by weighting the verification score and the relative evaluation score; and an image verification unit that performs verification of the input image on the basis of the integrated score.