A vehicle-mounted device includes a waiting time determination unit which determines a waiting time until the vehicle-mounted device transitions from a power-on state where a service providing function is performed to a power saving state where the service providing function is stopped while an engine of a vehicle is stopped, and a state transition unit which shifts the vehicle-mounted device from the power-on state to the power saving state after the waiting time has elapsed since stopping of an engine of the vehicle, and the waiting time determination unit changes the waiting time from a waiting time at a time of previous engine stopping.