To securely prevent from battery depletion and enable transfer data without troubling a user, a communication address data storage unit stores a communication address datum such as an IP address, a telephone number of the predetermined information management apparatus arranged outside an electric car. When an accessory switch of the electric car is in OFF state, it is judged by a charge state judge unit whether or not the battery is in charging. When it is judged by the charge state judge unit that the battery is in charging, a control unit controls a radio communication unit to execute at least one action of transmitting updatable data and receiving update data for updating the updatable data between the information management apparatus. As a result, the car-mounted information apparatus can communicate by radio with the information management apparatus outside the electric car while the battery is in charging.