1. A text mining server comprising: mining condition accepting means for accepting one or a plurality of document IDs and a user ID as mining conditions; characteristic word list preparation means for extracting characteristic words from one or a plurality of documents corresponding to the accepted document IDs and for preparing a characteristic word list; means for obtaining an unnecessary word dictionary corresponding to the accepted user ID; unnecessary word removing means for removing unnecessary words registered in the unnecessary word dictionary from the characteristic word list; and output means for outputting the characteristic word list as mining results from which the unnecessary words are removed via the unnecessary word removing means.