A data reading control unit select packets to be transmitted so that the number of packets that are transmitted per unit time does not exceed the number of packets that can be transmitted per unit time. The data reading control unit performs this packet selection according to the transmission amount per unit time calculated by a transmission amount calculation unit, the priority information in a priority storing unit, and the transmission queue information in a transmission queue information storing unit. The data reading control unit 109 reads pointers to the selected packets from a cycle transmission queue buffer, reads TS packets from a TS packet buffer according to the read pointers, and outputs the read TS packets to a transmission unit.