A meta-information storing section records a plurality of pieces of taxonomy data in ranks. A plurality of pieces of leaf meta-data respectively correspond to pieces of the lowest taxonomy data. A database records a plurality of pieces of real data which respectively correspond to pieces of leaf meta-data. A server control section searches for upper taxonomy data corresponding to the keyword included in a search request and acquires lower taxonomy data associated with the upper taxonomy data. The server control section is capable of repeatedly acquiring further lower taxonomy data until the lowest taxonomy data is specified, and as a result, acquiring leaf meta-data. The server control section samples real data corresponding to all of the leaf meta-data from the database and outputs it.