A question inference device comprises: an input unit inputting an inquiry from a user; a storage unit storing a plurality of questions prepared in advance and one or more keywords for identifying each question in association with each other; a choice unit referring to the storage unit and choosing a question associated with a keyword contained in the inquiry inputted by the input unit from among the plurality of questions; a computation unit computing the likelihood of each of the plurality of questions for the inquiry inputted by the input unit; an inference unit inferring, based on a choice result of the choice unit and a computation result of the computation unit, such a question that the user intends the substance of the question from among the plurality of questions; and an output unit outputting information based on an inference result of the inference unit.