PURPOSE: To make the driving power remain small and adjust the powder scattering width in diversified manners by accommodating power in a tank placed on a running device, mounting a supply pipe on the tank, furnishing the tank with a plurality of screw conveyors capable of working independently one another, providing a scattering part at the end of the conveyor, and furnishing a deaerating device on the oversurface of the tank.

CONSTITUTION: A supply pipe 6 is connected with a cement storing part, and a powder, for example cement, is supplied to a tank 2 together with a compressed air. This elongates a deaerating device 30, which is enlarged in cylindrical form. When the supply of the compressed air is stopped, the cement is settled quickly by its deadweight to the lower part of the tank 2, so that it is possible to transfer to the scattering work in a short time. This is followed by determination of the quantity of screw conveyors 14 to be in operation in accordance with the cement scattering width. When a hydraulic motor 17 is rotated, screw wanes 13 are awed. When the cement is transported by the wanes 13a and reaches an exhaust cylinder root 12, ansporting speed is increased by vanes 13b, and finally a determined quantity of cement drops from the scattering part 22. The cement is scattered uniformly on the ground by a dispersing plate 23.