PURPOSE: To suppress the nonuniformity of the intra-surface film thicknesses of deposited thin films by providing the circumference of the central through-hole of a susceptor of the thin film deposition device utilizing CVD with through- or non- through-holes of the area narrower than the area of the above-mentioned through-hole.

CONSTITUTION: A boat and semiconductor wafers placed on the susceptor mounted thereon are housed into a reaction tube and gases are supplied into the reaction tube to deposit the thin films. The susceptor 3 is formed to a circular shape and is provided with the through-hole 1 at its center. The many small through- or non-through-holes each having a circular section are distributed in triple concentrical form in the positions shown in fig. nonuniformly within the plane. The wafers do not come into tight contact with the susceptor 3 in the parts of the through-hole 1 and the small holes 2 when the wafers are placed on both surfaces of the susceptor 3 in tight contact therewith and, therefore, the ratio of the heat conduction from the susceptor 3 is small and the temp. rises hardly. Since the throwing density of the RF electric power decreases, the generation of the heat itself decreases and the thickness of the films deposited in these parts decreases. The intra-surface distribution of the film thickness is thus uniformalized.