A data read apparatus which, when reading data in a data region sequentially, consults information pieces indicative of positions of information pieces concerning files to identify a position of an information piece concerning a file corresponding to a data piece at a reading position, consults an information piece concerning the file at the identified position to calculate an output position in a temporary memory region to which the data is to be outputted, delivers the data read out of an area in the data region to the output position, decides whether files corresponding to outputted data are all present in the temporary memory region and delivers the files to a backup region in a unit of file when the presence of all files is determined.