An estimation device includes at least one of a facial skin temperature acquisition unit and a facial photographic image acquisition unit, and an evaluation unit. The facial skin temperature acquisition unit acquires, in time-series, facial skin temperature data of a facial surface of a subject to which brain function activation information is provided. The facial photographic image acquisition unit obtains, in time-series, facial photographic image data obtained by imaging the facial surface of the subject to which the brain function activation information is provided. The evaluation unit evaluates a degree of interest of the subject based on at least one of the facial skin temperature data acquired by the facial skin temperature acquisition unit and the facial surface photographic image data acquired by the facial surface photographic image data acquisition unit.
