A vehicular communication device switches over a communication method between the OFDM method and the SS method. A PLC master set includes a LAN communication unit for performing data communications with control units such as an engine control ECU via an in-vehicle LAN. In the PLC master set, a microcomputer acquires the operating states of parts of the vehicle from various control units through the LAN communication unit, and uses the acquired operating states and control information stored previously to enable data communications without being affected by noises occurring in the parts of the vehicle by notifying a PLC slave set of a communication method in the PLC communication unit and a communication method with a sub-carrier set prohibited from use being set when a communication method is the OFDM method.