There is provided a technique that includes: substrate mounting plate where substrates are arranged circumferentially; rotator rotating the substrate mounting plate; gas supply structure disposed above the substrate mounting plate from center to outer periphery thereof; gas supplier including the gas supply structure and controlling supply amount of gas supplied from the gas supply structure; gas exhaust structure installed above the substrate mounting plate at downstream side of the gas supply structure in rotation direction; gas exhauster including the gas exhaust structure and controlling exhaust amount of gas exhausted from the gas exhaust structure; and gas main component amount controller including the gas supplier and the gas exhauster and controlling gas main component amount in the gas supplied from the gas supply structure to the substrates and the gas main component amount in the gas supplied to the substrates from the center to the outer periphery of the mounting plate.