Abstract: There is disclosed a vehicle window-opening device for quickly opening a vehicle window manually or automatically. If the vehicle should fall into a sea or river, the window-opening device prevents the passengers from being confined within the vehicle. If the vehicle is fitted with an air bag system, any secondary accident can be prevented. More specifically, there is provided a device for opening a window mounted in a door of a vehicle having a window-driving mechanism for causing the window to slide up or down, the device comprising a gas source, a gas-ejecting mechanism for ejecting the gas of the gas source manually or automatically, and an actuator actuated by an ejected gas from the gas-ejecting mechanism. Wherein a driving force of the actuator is transmitted to the window-driving mechanism, thus driving the window open.