An extraction device according to the present application includes an acquisition unit and a notification unit. The acquisition unit makes a web search engine execute extraction processing based on an arbitrary query received from an information user and acquires, as an extraction result, the number of users corresponding to the arbitrary query from behavior histories of users to be processed. The notification unit notifies the number of users acquired by the acquisition unit to the information user who posts the arbitrary query. More specifically, based on a query related to setting of a condition about behavior or an attribution of the user, the acquisition unit acquires the number of users corresponding to the query.