By means of a low-pressure-plasma spraying method, silicon-based material films have been prepared on the substrates with and without water-cooling and with various hydrogen gas flow rates in a mixtured gas plasma. The relationship between the physical properties of the films and the growth conditions has been investigated by an X-ray diffraction analysis, a Raman scattering spectroscopy, and an electric conductivity measurement. It was found that the films were almost porous polycrystalline silicon, and contained a slight amount of smaller microrystalline silicon. The size of the microcrystalline silicon slightly decreased with increasing the hydrogen gas flow rate, and in the case of the water-cooled substrate. The existence of a small amount of amorphous region was also suggested at higher hydrogen gas flow rate. Furthermore, the change in theelectric conductivity was observed, which was related to the structural changes.