SIMILAR DOCUMENT RETRIEVING DEVICE

PURPOSE:To efficiently perform retrieval with a high precision by providing a document input part, an index extracting part, etc., to retrieve a similar document without setting a keyword, a logical formula, or the like and developing indexes as a thesaurus. CONSTITUTION:Document information inputted from the external is converted to code information adapted to this device by a document input part 1, and a sentence inputted from the document input part 1 is divisionally written and is divided into word units by a modification analyzing part 2, and modification analysis of individual words is performed. The degree of resemblance of documents is judged in consideration of degrees of importance of indexes given by an index extracting part 3 and semantic closeness of synonyms developed as a thesaurus and in accordance with the degree of resemblance of modification structures. Thus, similar documents are efficiently retrieved from the data base of a full text with a high precision.