1. A device for identifying whether a specified object is displayed in an image, the device comprising: a plurality of score calculators each configured to extract a feature quantity from the image, and calculate a score using the extracted feature quantity and a model of the specified object, the score representing a reliability that the specified object is displayed in the image; a score-vector generator configured to generate a score vector having the scores calculated by the score calculators as elements thereof; a cluster determiner configured to determine, based on previously determined clusters in which the score vector is classifiable, one of the clusters to which the score vector belongs as a target cluster; and an object identifier configured to have identification conditions previously determined for the respective clusters, and identify whether the specified object is displayed in the image based on one of the identification conditions, the one of the identification conditions being previously determined for the target cluster determined by the cluster determiner.