In a power line communication system, a control device sets an intra-breaker communication period during which communication is performed between communication terminals connected to a single breaker, and an inter-breaker communication priority period during which communication is performed between communication terminals connected to different breakers from each other. The control device operates filters so that the filters allow signals that travel via breakers to pass through the filters during the inter-breaker communication priority period, and so that the filters block signals that travel via breakers from passing through the filters during the intra-breaker communication period.