A receiving device is used that includes a main tuner 11, a sub-tuner 12, and a control unit 13 is used. The main tuner 11 and the sub-tune 12 have local oscillators 25, 45, respectively, for generating local oscillation signals according to frequencies of selected channels, and extract signals on the selected channels by using the local oscillation signals. The control unit 13 judges whether the frequency of the channel selected by the main tuner 11 is identical to the frequency of the channel selected by the sub-tuner 12. When it is judged that they are identical, the control unit 13 stops the generation of the local oscillation signal by the local oscillator 45 of the sub-tuner 12 and causes the sub-tuner 12 to extract the signal on the selected channel by using the local oscillation signal generated by the local oscillator 25 of the main tuner.