Abstract: A content transmission device receives broadcast data composed of a plurality of contents from another broadcasting station, converts the broadcast data to own-station broadcast data, and transmits the converted broadcast data. The content transmission device stores a plurality processing models, each having corresponding identity information, composition information indicating content scheduled for inclusion in the broadcast data, normal-case processing information, and irregular-case processing information. The content transmission device acquires identity information from an external device that manages the broadcasting schedule for the broadcast data, and selects the corresponding processing model. The content transmission device detects received broadcast data portions different from those indicated by the composition information in the selected processing model.