A weight estimation unit estimates, from a person's image in which a person is included, a weight of a human body part of the person in accordance with an existence probability of the human body part of the person. A feature creation unit creates a feature for verification based on a weight of the person's image and a weight estimated by the weight estimation unit. A verification feature storage unit stores a feature of the person who is the object of verification as a verification feature. A person verification unit compares the feature for verification created by the feature creation unit and the verification feature stored in the verification feature storage unit.