An ONU device is disclosed. The ONU device is capable of channel switching in a broadcasting-telecommunications convergence system where digital broadcasting signals of channels are switched according to subscribers, converged with communication signals destined for the subscribers, and transmitted to the subscribers. In the ONU device, a channel information extractor extracts channel switching information about digital broadcasting contents included in the digital broadcasting signals, a channel switching information database stores the extracted channel switching information and provides the channel switching information according to channel selection information from a subscriber received from a zapping processor, and the zapping processor outputs a control signal for channel switching according to the channel switching information.