PROBLEM TO BE SOLVED: To provide a substrate processing method, a pressure control device and a substrate processing system for expanding a pressure control range in a chamber. SOLUTION: In a substrate processing system 1, a chamber 10, a gas supply unit for supplying a processing gas to the chamber, a first pipe 81 for low pressure control, a first APC valve 82, a turbo molecular pump 83, a first. The first exhaust line L1 in which the isolate valve 84 and the dry pump 85 are arranged, and the second isolate valve 86, the second APC valve 87 and the dry pump 85 are arranged in the second pipe 80 of the high pressure control. The route has a second exhaust line L2. The second pipe has a smaller cross-sectional area than the first pipe. Switching between low pressure control and high pressure control is controlled by the control unit. [Effect] This makes the pressure in the chamber 10 mTorr to 100 Torr or more, including the pressure higher than 800 mTorr, which was difficult in the past. It can be controlled in a wide pressure band. [Selection diagram] Fig. 2
展开▼
