A document classification and inspection system obtains digital information recorded in plural computers or servers, extracts a document from document information configured by plural documents, included in the obtained digital information, calculates a score indicating the strength of connection between the document and a classification code for the extracted document in a time-series manner, detects a time-series score change from the calculated score, and inspects the degree of relevance between an inspection case and the extracted document from the detected time-series score change.