Abstract: A spraying device includes a cap and two barrels coupled to form a structure. Compressed air can be supplied from the rear end of the structure. A cup for containing paint materials is coupled to the front end of the structure. A nozzle is disposed in the cap for controlling a passage of the paint materials. A valve device is actuated by a knob to open an air passage of the structure. When the knob is pushed rearward, the valve device is opened so that the compressed air may flow out of the cap, and when the knob is further pushed rearward, the nozzle can be opened so that the paint materials can be sucked to flow out of the cap when the compressed air flows out of the cap.