The sandblasting is known for a surface processing techniques in industrial world. Recently, the technique applies to micro processing for electric circuit. But the characteristics of the technique using the gas-solid impinging jet depend on the length between the sandblasting nozzle and the works. Especially the technique has characteristics to process, which the surface of the works shows uneven distribution for the short length between the sandblasting nozzle and the works. The characteristics are affected by the characteristics of the flow fields of the impinging jet, and the change of that affects on the trajectories of the solid particles in the gas-solid. In this paper, experiments and numerical simulations clear the flow fields of the gas-solid impinging jets, and performance of the sandblasting nozzle is estimated. Cylinder Bundle, Numerical Calculation