A facial expression label is assigned to face image data of a person with high accuracy. A facial expression data set storage unit (110) stores a facial expression data set in which the facial expression label is assigned to the face images in which people belonging to various groups show various facial expressions. A facial expression sampling unit (11) acquires a face image in which a person belonging to the desired group shows a desired facial expression. A representative feature quantity calculation unit (12) determines a representative feature quantity for each facial expression label from the face image of the desired group. The target data extraction unit (13) extracts target data from a facial expression data set. A target feature quantity calculation unit (14) calculates a target feature quantity from the target data. A corrected label determination unit (15) determines a corrected label to be assigned to the target data by comparing the target feature quantity and each of the representative feature quantities. The label assignment unit (16) assigns a corrected label to the target data.