Channel selection unit selects a channel of a desired program from a digital broadcast signal in which an ECM and an EMM are multiplexed. Separation unit separates the ECM and the EMM. EMM decoder decodes the EMM. A first key is obtained from the decoded EMM. ECM decoder decodes the separated ECM using the first key. A second key is obtained from the decoded ECM. Viewing enabling determination unit determines whether or not to enable viewing of the program. A system controller communicates with an information server through a network interface part at the time of work key non-setting, and an OSD display processing unit is made to generate an image for displaying information provided.