The content receiving unit (201) receives IP packets (Ethernet frames) that include broadcast content. The assigning unit (202) assigns, based on a given method, received Ethernet frames to the A-layer and the B-layer that are different digital broadcast layers. The Ethernet frames assigned to the A-layer are encapsulated by the A-layer processing unit (203), and transmitted to a terrestrial digital broadcast network together with encapsulation format information. Meanwhile, the Ethernet frames assigned to the B-layer are encapsulated by the B-layer processing unit (204), and transmitted to the terrestrial digital broadcast network together with encapsulation format information.