File system and file management method

The present invention relates to a file system using a disc memory storage and a method of managing the file system. Just like the ordinary server, a first block table Tbl with the offset number of the file to be written in matched with the block number Dij of the data block is provided, and the data stored in the memory is read out on the basis of the contents of the first block table Tbl. On that file system, a second block registering means is provided which couples the block number allotted to the file to write and the offset number and, in case of consecutive block numbers, prepares a second block table Tb2 in which the first block number of the consecutive block numbers is paired with the offset number. A second take-out means is also provided. When consecutive data are to be read out, the second block take-out means arithmetically processes, on the basis of the contents of the second block table Tb2, the block numbers Dij to be read out and hands over the results to the data read-out means.That substantially reduces the access and processing time for read-out at the block table and makes the reading out of data highly efficient.