A liquid introducing device transfers a fixed amount of liquid medicine into atomized particles. The liquid medicine is connected to the liquid introducing device which allows the users to quickly replace the bottles and avoid cross infection between different medicines. The liquid introducing device is powered by electric power to atomize the liquid quickly. The liquid introducing device includes a chamber which cooperated with an electro-magnetic valve switch which controls a fixed amount of air in the chamber such that the fixed amount of the air can be pressurized and output stably. The pressurized air passes through the tube without delay and loss.
