PURPOSE: To prevent the adhesion of dust on the rear of a semiconductor substrate, and to improve reliability and yield by forming a susceptor in structure in which the outer circumferential end section of the rear of the semiconductor substrate is supported under a contact state.

CONSTITUTION: A substrate supporter 3 is installed between a heating source 1 and a gas supply port 2 in a system. The substrate supporter 3 consists of a plate made of inconel, and a recessed section 5 smaller than the outer circumferential size of a semiconductor substrate 4 and taking a similar figure to the outer circumferential shape of the substrate 4 is shaped where the semiconductor substrate 4 is placed. The semiconductor substrate 4 is put on the susceptor 3 having such structure by using an automatic carry-out-in machine section 6 so as to completely bring the recessed section 5 to a closed state. A contact surface between the semiconductor substrate 4 and the susceptor 3 extends over several mm in the outer circumferential end section of the rear of the semiconductor substrate, and a raw material gas is prevented from creeping to the rear, thus remarkably reducing dust adhering on the rear.