To prevent the content of a displayed screen from turning to the content being far from an operator' sensory immersion, in a car navigation system wherein a screen of content relative to decelerating magnitude during deceleration is displayed on a display means.

Each time when brakes are applied to a vehicle, deceleration at that time is detected, and speed change is detected until the vehicle stops. The speed change is patterned as damping characteristic. When the brake is applied to the vehicle, deceleration at the time of starting deceleration is detected, and regular deceleration or slam on the brake is decided. Application to the patterned damping characteristic is performed, Whether it is the slam on the brake is decided, and display is performed corresponding to decision result.