An image management device, comprising: an image acquisition unit adapted to acquiring an image group; an object detection unit adapted to detecting, for each image acquired by the image acquisition unit, one or more objects included in the image; an object sorting unit adapted to sorting the objects detected in each image acquired by the image acquisition unit into one of a plurality of clusters (701a-c), according to an object feature amount representing features of each of the object; an object priority evaluation unit (213,214) adapted to calculating an object priority for each of the objects, by calculating an evaluation value for the object from an accuracy representing relevance of the object to a relevant cluster and the relative quantity of objects belonging to the relevant cluster; and an image priority evaluation unit adapted to calculating an image priority for each image by summing object priorities calculated for the objects included in the image, wherein the object priority evaluation unit (210,212,214) is adapted (i) to calculate a similarity factor that indicates how similar the object feature amount of the object is to a cluster feature amount of the relevant cluster, wherein the cluster feature amount is a representative value of object feature amounts of objects in the relevant cluster, (ii) to calculate, when the image includes another object sorted into a cluster other than the relevant cluster, a co-occurrence degree indicating a count of co-occurrence of the object and said another object in the images of the image group, and (iii) to calculate the accuracy based on the similarity factor and co-occurrence information that includes the co-occurrence degree. an image acquisition unit adapted to acquiring an image group; an object detection unit adapted to detecting, for each image acquired by the image acquisition unit, one or more objects included in the image; an object sorting unit adapted to sorting the objects detected in each image acquired by the image acquisition unit into one of a plurality of clusters (701a-c), according to an object feature amount representing features of each of the object; an object priority evaluation unit (213,214) adapted to calculating an object priority for each of the objects, by calculating an evaluation value for the object from an accuracy representing relevance of the object to a relevant cluster and the relative quantity of objects belonging to the relevant cluster; and an image priority evaluation unit adapted to calculating an image priority for each image by summing object priorities calculated for the objects included in the image, wherein the object priority evaluation unit (210,212,214) is adapted (i) to calculate a similarity factor that indicates how similar the object feature amount of the object is to a cluster feature amount of the relevant cluster, wherein the cluster feature amount is a representative value of object feature amounts of objects in the relevant cluster, (ii) to calculate, when the image includes another object sorted into a cluster other than the relevant cluster, a co-occurrence degree indicating a count of co-occurrence of the object and said another object in the images of the image group, and (iii) to calculate the accuracy based on the similarity factor and co-occurrence information that includes the co-occurrence degree.