To prevent the product made by incomplete reaction of raw material gas from sticking to the adjacent lower portion of a substrate carrying hole by locating the lower edge of the substrate carrying hole above the surface of a substrate held by substrate holding means.

A raw material gas G taken in between a top plate 3 and a straightening plate 8 is uniformly supplied to the surface of a wafer W through the a plurality of discharge holes in the straightening plate 8. Then, the raw material gas G is efficiently supplied to the surface of the wafer W by the wafer W and a mount plate 15 which are rotating at a high speed, and a thin film such as Si monocrystal or the like is formed. Part of the raw material gas G supplied to the surface of the wafer W is discharged in a horizontal direction to the outer side by the high speed rotation of the wafer W and deflected downward by a vacuum exhaust flow from the exhaust hole 5. Since the lower end of a wafer carrying hole 22 is formed above the surface of a wafer W, the raw material gas G hardly comes into contact with the vicinities of the wafer carrying hole 22 so that product by imperfect reaction is hardly generated.