The present invention has been achieved to provide a method and apparatus for speedily and homogeneously fabricating polycrystalline silicon films or similar devices at low cost. A silicon target is attached to a water-cooled electrode, while a substrate made of a desired material is set on the other, heated electrode. When atmospheric pressure hydrogen plasma is generated between the two electrodes, silicon atoms will be released from the low-temperature target on the side and deposited on the high-temperature substrate. A doped silicon film can be created by using a target containing a doping element. Since there is no need to handle expensive and harmful gases (e.g. SiH4, B2H6 and PH3), the apparatus can be installed and operated at lower costs. In an application of the film producing method according to the present invention, an objective substance can be selectively purified from a target containing a plurality of substances.