A loss calculation element calculates a loss of a feature vector for each class, the feature vector indicating a feature of data belonging to the class. A loss difference calculation element calculates a sum of differences of losses between the classes based on the loss calculated for each class. A recognition dictionary creation element creates a recognition dictionary based on a total sum of losses calculated for the classes and the total sum of loss differences between the classes. The recognition dictionary creation element corrects, on a basis of an input feature vector, a recognition dictionary so as to minimize a sum of the total sum of losses for the classes calculated by the loss calculation element and the total sum of loss differences between the classes calculated by the loss difference calculation element, and the pattern classification element classifies a pattern of data using the corrected recognition dictionary.