A multitrack recorder capable of setting one track or more to a monaural type or a stereo type has a storage unit that stores a history of track-type changing-and-setting operations and operations entailing erasure or changing of audio data stored on each track and that stores specifics of the track-type changing-and-setting operations and the audio data erased or changed along with performance of operations in association with each operation, and a change unit that changes audio data stored in each track, and a type of the track, to audio data that were stored in each track, and a type of the track, before performance of a specified operation.