PROBLEM TO BE SOLVED: To classify postures of human bodies with high accuracy.SOLUTION: Postures of human bodies are classified into a plurality of posture types. When a plurality of first measurement values 31, which measure the inclination of a subject 11 in a plurality of directions, are obtained for each posture type, a parameter calculation unit 3 calculates, for each posture type, parameters 21 for generation of a probability model 22 of measurement values that follows a multi-dimensional normal distribution on the basis of the plurality of first measurement values 31 for each posture type, and stores the parameters 21 in a storage unit 5. When second measurement values 32, which measure the inclination of the subject 11 in the plurality of directions each same as for the first measurement values 31, are also obtained, a classification processing unit 4 classifies the posture of the subject 11 into any of the plurality of posture types on the basis of the probability model 22 for each posture type generated based respectively on the second measurement values 32 and the parameters 21 stored in the storage device 5.
