Retrieval is completed in a short time for presenting a retrieval result of a document file, which satisfies a retrieval condition, to a user having the authority to perform predetermined processing. A retrieval device includes a correspondence information generating unit for generating correspondence information indicating membership of a user to a group, an index information generating unit for generating index information by extracting user identification information associated with group identification information included in authority information provided to a document file from the correspondence information, the index information including information in which the extracted user identification information is associated with the document file, and a retrieving unit for retrieving a document file, which satisfies a retrieval condition whose input is received by an input receiving unit and in which the user identification information included in the index information coincides with user information whose input is received.