In order to manage the various types of attribute information within the storage system, the storage system includes the following databases within a file-access controlling memory: a database for managing index information for managing contents of the files, and an index retrieval program, a database for managing the attribute information on the files, and a database for managing storage positions of blocks configuring a file. When the storage system receives an access request to a file, the utilization of these databases allows the storage system to make the access to the access-target file.