A method of processing an application in a digital broadcast receiver connected with an interactive network, the method comprising: receiving, from a broadcast network, broadcast audio/video content and application information table data in a current channel or service, wherein the application information table 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 at least one application is able to be accessed by using at least one secondary device while displaying video data included in the broadcast audio/video content, wherein the indicator is overlaid within the video data; searching a specific secondary device connected to the digital broadcast receiver via Universal Plug and Play, UPnP, wherein identification for the specific secondary device is registered in a memory of the digital broadcast receiver; extracting additional information on multiple applications; displaying an application list according to the extracted additional information, wherein the application list comprises time information required for downloading each of the multiple applications by the specific secondary device and an item for identifying pay or free of each of the multiple applications; transmitting the application list identifying the multiple applications to the specific secondary device; receiving a request signal for a specific application in the application list from the specific secondary device; and transmitting the requested application or an IP address of the requested application to the specific secondary device. receiving, from a broadcast network, broadcast audio/video content and application information table data in a current channel or service, wherein the application information table 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 at least one application is able to be accessed by using at least one secondary device while displaying video data included in the broadcast audio/video content, wherein the indicator is overlaid within the video data; searching a specific secondary device connected to the digital broadcast receiver via Universal Plug and Play, UPnP, wherein identification for the specific secondary device is registered in a memory of the digital broadcast receiver; extracting additional information on multiple applications; displaying an application list according to the extracted additional information, wherein the application list comprises time information required for downloading each of the multiple applications by the specific secondary device and an item for identifying pay or free of each of the multiple applications; transmitting the application list identifying the multiple applications to the specific secondary device; receiving a request signal for a specific application in the application list from the specific secondary device; and transmitting the requested application or an IP address of the requested application to the specific secondary device.