Patent ID: 8828141

Claim:
A substrate processing apparatus for supplying a processing gas to a surface of a substrate, for supplying an inactive gas, and for forming a thin film on the surface of the substrate, the substrate processing apparatus comprising: a processing chamber configured to process substrates stacked in multiple stages in horizontal posture; a processing gas supply unit configured to supply the processing gas to the inside of the processing chamber from a processing gas source; an inactive gas supply unit configured to supply the inactive gas to the inside of the processing chamber from an inactive gas source; an exhaust unit configured to exhaust an atmosphere of the inside of the processing chamber; a preliminary chamber which is formed so as to extend running along an inner wall of the processing chamber in the stacking direction of the substrates, the preliminary chamber being configured to project from an outer radius of the processing chamber outward in a radial direction of the processing chamber, the preliminary chamber being connected to the processing chamber by side walls; wherein: the processing gas supply unit has a processing gas supply nozzle which is provided inside the preliminary chamber and extends running along an inner wall of the preliminary chamber in the stacking direction of the substrates and is configured to supply the processing gas to the inside of the processing chamber, the inactive gas supply unit has a pair of inactive gas supply nozzles which are provided inside the preliminary chamber and extend running along the inner wall of the preliminary chamber in the stacking direction of the substrates and so as to sandwich the processing gas supply nozzle from both sides thereof, along the circumferential direction of the substrates, and which are configured to supply the inactive gas to the inside of the processing chamber from the inactive gas source, the inactive gas supply nozzles supply only an inactive gas, and there are no intervening sources between the inactive gas source and the inactive gas supply nozzles.