A recording/reproducing device, enabling transfer (move process) of a content any number of times between devices while keeping the most appropriate high image quality for each device in compliance with copyright protection, includes a content management unit (13) for managing the content data so as to make reproduction of the content data in a recording/reproducing unit (5) impossible simultaneously with transfer when the content data, from which copying is prohibited, is transferred to an external device, and managing the content data in the recording/reproducing device so as to enable the reproduction of the content data in the recording/reproducing device if the content data transferred from the external device has been transferred from the recording/reproducing device to the external device and is now in an irreproducible state in the recording/reproducing device.