A powdered material spraying device comprising a quantitative spraying device provided for a material discharge port of the powdered material storage hopper via a material feed valve, a cover being provided for the material feed port of the powdered material storage hopper. The spraying device includes a cylindrical body connected with the material discharge port of the powdered material storage hopper, an elastic membrane with a penetrating aperture provided so as to form a bottom of the cylindrical body at its lower opening end, and a dispersion chamber connected under the lower opening end of the cylindrical body via the elastic membrane. The dispersion chamber has a pulsating vibration air supply port for supplying a positive pulsating vibration air to the dispersion chamber and a discharge port. A bypass pipe is connected between the cylindrical body and the dispersion chamber and the powdered material is sprayed from a tip end of a conduit connected with the discharge port of the dispersion chamber.