A cognitive function evaluation device includes an acquisition unit that acquires body motion data representing a body motion of a person to be evaluated during walking； a calculation unit that calculates a displacement of a body of the person to be evaluated during walking based on the acquired body motion data； and an evaluation unit that evaluates a cognitive function of the person to be evaluated based on a frequency peak representing a cycle of walking of person-to-be-evaluated obtained by performing a frequency analysis on the calculated displacement, and to output the evaluation result.
