An apparatus and a method, which make it possible to collect a plurality of the contents authored for DVD to record easily them on a large-capacity information record medium and to increase a data rate in reproducing the recorded contents, perform the processes of: creating source packets from a disk image file; collecting them to form arrangement units 320; collecting them to form ECC clusters; collecting sectors of the DVD to form a sector group, thereby storing it while bringing it into correspondence with a predetermined number of source packets; adding a control packet to this to form units of conversion; collecting them to bring them into correspondence with an integral number of the arrangement units 320; and storing a cluster-number, at which a leading sector of the sector group of the DVD is stored in the control packet; wherein the source packets are brought into correspondence so that a leading portion of the file system area coincides with both a leading portion of the arrangement unit and a leading portion of the error correction cluster and the disk image file is recorded using units of the length so that the length causes a boundary of the units of conversion to coincide with a boundary of the ECC clusters.