A digital broadcast receiver is disclosed. The method of processing an application in a digital broadcast receiver connected with an interactive network includes receiving, from a broadcast network, broadcast audio/video (A/V) content and application information table (AIT) data, wherein the AIT data includes a linkage descriptor, parsing the linkage descriptor, wherein the linkage descriptor comprises a field identifying a type of at least one secondary device able to process the application, displaying an indicator informing that the application is able to be accessed by using at least one secondary device, searching at least one secondary device connected to the digital broadcast receiver, receiving a request signal for the application, and transmitting the application or an IP address of the application to the secondary device.