There is provided a cerebrum evaluation device for evaluating the state of the cerebrum of a subject by analyzing a speech signal of the subject by using chaotic signal processing utilizing the periodicity of the signal. The cerebrum evaluation device evaluates the state of the cerebrum according to the speech signal uttered by the subject. The cerebrum evaluation device includes: a statistic information database containing chaotic index values of speech signals of a plurality of subjects; a speech signal acquisition unit for acquiring a speech signal; a chaotic index value calculation unit for calculating a chaotic index value of the speech signal by the chaotic signal processing utilizing the periodicity of the speech signal acquired; an evaluation unit for evaluating the state of the cerebrum of the subject according to the calculated chaotic index value by referencing the statistic information database; and an output unit for outputting the result evaluated by the evaluation unit.