A data recording device of the present invention acquires passwords of individual recording media attached to a plurality of medium attaching units from a password storage unit which stores the passwords set to the recording media having a password locking function, the device judges whether or not the individual recording media are accessible by a RAID recording system by use of the acquired passwords, and the device accesses data of each recording medium by the RAID recording system in a case where the medium is accessible by the RAID recording system.