COGNITIVE FUNCTION EVALUATION DEVICE, COGNITIVE FUNCTION EVALUATION METHOD, AND PROGRAM 5 Cognitive function evaluation device (100) includes: storing unit (102) storing reference data on the relationship between the periodicity of a body movement of a person walking and the cognitive function level of the person; 10 acquiring unit (101) that acquires body movement data on the detected body movement from body movement sensor (105) that detects the body movement of subject (2) walking; and calculating unit (103) that calculates the periodicity of the body movement while walking from the acquired body movement data and checks the calculated periodicity against reference data (110) stored in storing 15 unit (102) so as to identify the cognitive function level corresponding to the calculated periodicity. Figure 2