A data unit group handling apparatus which handles a file system for storing a plurality of files defined by different kind of file formats, and at least one of the files is a data unit group which is defined by a predetermined file format, includes data units and can be located in any location in the file system. In the apparatus, at least one data unit group is retrieved from the file system in accordance with the file format, a selection instruction is received from a user to select at least one of the data unit group from the retrieved at least one data unit group, retrieval condition to retrieve at least one data unit is also received, and at least one of the data unit matching to the received retrieval condition from the at least one of the data unit group which is selected in accordance with the received selection instruction.