An information signal copy managing method for properly protecting the copyright of information signals and, at the same time, guaranteeing user advantages in copying information signals within a limited range. Information indicative of the start and end of each piece of information content covered by copyright is superimposed thereon as electronic watermark information. The resultant information signal is transmitted. When the received information signal is copied, both the information indicative of the start of the information content and the information indicative of the end thereof are detected from the electronic watermark information, determining the completion of copying. Thus, copying of information content is managed.