1. A corpus generation device comprising: a web page acquisition unit that acquires a web page including description sentence data regarding a presentation target; a reference word acquisition unit that acquires a reference word that is an attribute value regarding the presentation target from the web page; an attachment unit that extracts a broader word belonging to a layer above the reference word acquired by the reference word acquisition unit from a storage unit that stores hierarchical relationship information indicating a hierarchical relationship between attribute values, and attaches an attribute tag corresponding to the reference word to the broader word included in the description sentence data when the broader word is included in the description sentence data; and an output unit that outputs, as corpus data, the description sentence data to which the attribute tag is attached by the attachment unit.