Abstract: Problems are posed by slip prevention particle injection devices by wheels of railway rolling stock. Namely, if the injected quantity of slippage-preventing particles is adjusted so as not to be excessive and to be a suitable quantity, it is not possible to obtain a predetermined injection pressure and it is not possible to inject the particles at the target location. The injector device of the present invention is constituted by providing an air through-flow duct 5 inside a particle retainer tank 1, and connecting an air supply duct 17 to this air through-flow duct 5. In the above mentioned tank 1, in addition to an air inflow duct 6 being provided in the vicinity of the inlet side of the air through-flow duct 5, an air discharge duct 18 is provided in the vicinity of the outlet side of the air through-flow duct 5. This air inflow duct 6 and air discharge duct 18 are connected to the air through-flow duct 5 and one end of these ducts 6 and 18 is open into the tank 1.