An information search device includes: a path field generating part that, for each node, generates a path field in which paths with the node as an origin are connected; an index generating part that, for each element configuring graph structure information, generates a posting list as a list of information composed of a node having a path field including the element and location information representing a location where the element appears in the path field, and generates an index repository in which the element and the posting list are associated; a search path generating part that generates a search path representing a search condition; and a searching part that extracts a node having a path field satisfying an appearance sequence of elements included in the search path based on the location information of the posting list.