A document type identifying apparatus includes in advance a database storing therein keywords used as keys that identify document types in association with each document type. The document type identifying apparatus aligns word strings written on a document and generates partial keyword strings for each keyword by using the keywords stored in the database. The partial keyword strings are to be checked for matching with the word strings written on the document. Then, the document type identifying apparatus checks matching of the grouped and aligned word strings with the partial keyword strings and obtains, for each keyword, each number of matched words with the highest matching rates between the grouped word strings that are successfully matched and the partial keyword strings. Then, each number of matched words is used to calculate each evaluation value to determine the document type.