When a plurality of types of copyright information are detected on a disk or the like, a content playback device and method can appropriately control playback of content in accordance with the copyright information. As the content playback device, a digital watermark detection device attempts to detect watermark information in blocks that make up the content, and a result storage subunit (401) stores result information constituted from detected watermark information and frequency information indicating how often the watermarks appear. Each time watermark information is detected in one of the blocks, a comparison subunit (402) compares the detected watermark information to the watermark information in the result information, and judges whether updating the result information is necessary with reference to a predetermined condition. An update subunit (403) performs an update, and a control unit (307) performs a playback restriction of the content with use of the result information.