An in-vehicle emergency call apparatus capable of performing an emergency call operation when electric power supply from a vehicle battery is cut is provided. The in-vehicle emergency call apparatus includes a first electric power supply line system causing an electric power supply unit to supply electric power to an emergency notification detection unit and an control unit. A second electric power supply line system is provided that causes the electric power supply unit to supply the electric power to the radio-communication unit. The second electric power supply line system is provided independently of the first electric power supply line system. A first capacitor coupled with the first electric power supply line system is capable of being configured to have a small capacitance.