A realtime data recording method allows recovery of recorded file data upon occurrence of a fault, for use as a readable file. Prior to recording, initial management data are generated such that the entire area on a recording medium 1 is reflected as a recording range. After the initial management data has been recorded, data recording is started. During the recording, a writing status of the recording medium (or apparatus) is set as in-writing status, and realtime sector information generated in parallel to data recording is recorded in a non-volatile memory for management of a recording status. Upon restarting after a recording fault, the in-writing status of the recording medium 1 is read to see if the medium has been set open, and inconsistency between the recording information of the sector information and the in-writing status recording information is detected. Correct management data is recorded and re-recorded onto the recording medium.