1. An image evaluation device comprising: an image feature extraction unit that extracts image features from a plurality of images; an evaluation information acquisition unit that acquires evaluation information, the evaluation information containing results of evaluations of the images performed by users including a subject user; a generation unit that generates relational information based on the image features and the evaluation information, the relational information showing relationship between the images, the users, and image feature groups into which the image features are classified; and an image social importance calculation unit that calculates an image social importance degree of each image based on the relational information generated by the generation unit, each image social importance degree showing a degree of importance to the subject user of the corresponding image.