An AV data recording apparatus and an AV data recording method are provided, in which even in the case of using the UDF file system, seeking can be minimized. The AV data recording method has file management information for managing continuous blocks on a disk as an extent, and dividing the extent into groups so as to manage the extent as a file, wherein a new directory is created on a disk, and a not recorded but allocated extent is kept as a reservation region for recording file management information.