There is provided an electric connector that is interposed between an in-vehicle wire cable and a train information transmission/reception apparatus. The in-vehicle wire cable includes a plurality of signal lines that transmit train information and an electrically-conductive shielded layer surrounding the signal lines. One end of a ground line is connected to the shielded layer. A casing ground is provided on a casing of the train information transmission/reception apparatus and a plurality of plug pins electrically connected to the signal lines are provided on the casing of the train information transmission/reception apparatus. The other end of the ground line is connected to an electrically-conductive connector case, which is a casing of the electric connector, and the connector case is grounded via the casing of the train information transmission/reception apparatus when the signal lines and the plug pins are electrically connected to each other.