A second IF signal is counted either directly or indirectly. An AFC operation is performed based on the counting result. A plurality of count periods (A1, C1) are provided within a video signal period (Y+H) including a horizontal blanking period, and the plurality of count periods (A1, C1) are randomly shifted for each field. An AFC operation is performed based on a plurality of counting results in a plurality of field periods which correspond to one cycle of an energy diffusion signal.