An audio apparatus contains a plurality of playable files stored in a database and organized in folders. The folders can be listed in a manner understandable at a glance even when viewed on a small display area and when the hierarchical structure shows a minimum level of detail. A folder selection section selects a folder from a database, and a directly-under-folder detection section detects if a playable file exists directly under a folder selected. A folder-under-folder detection section detects if a playable file exists directly under any folder located under the selected folder assuming no playable file exists directly under the selected folder.