To provide a detection device capable of, e.g., obtaining a list of genes whose expressions are commonly changed in response to administration of a specific drug or drugs, based on consideration of relationship (e.g., interacting relationship among genes) among genes, a list of proteins whose expressions are commonly changed in response to administration of a specific drug or drugs, based on consideration of relationship (e.g., interacting relationship among proteins) among proteins, and a list of users who purchased an identical product or products, based on consideration of relationship (e.g., friendship) among users, and so forth. A graph data obtaining unit (20) obtains graph data indicating a graph including a plurality of vertexes. A vertex data obtaining unit (22) obtains vertex data that correlates an information item to a vertex. Based on the graph data and the vertex data, a subgraph detection unit (24) detects a subgraph that is a subgraph of the graph in which information items correlated to the respective vertexes in the subgraph have predetermined relationship.