Apparatus for and method of manufacturing a semiconductor device, and cleaning method for use in the apparatus for manufacturing a semiconductor device

An apparatus for manufacturing a semiconductor device, comprising:

• a process chamber which holds a substrate to be subjected to a prescribed process;
• a gas inlet pipe which is connected and communicates with an interior of the process chamber and which introduces a process gas for use in the process, into the process chamber;
• a gas outlet pipe which is connected and communicates with the interior of the process chamber and which discharges the gas from the process chamber to outside the process chamber;
• component-measuring devices which are provided at two or more positions selected from the group comprising of a position in the process chamber, a position in the gas inlet pipe and a position in the gas outlet pipe, and which measure components of the gas in the process chamber or at least two different gases selected from the group comprising of gas in the process chamber, gas to be introduced into the process chamber and gas discharged from the process chamber;
• concentration-measuring devices which are provided at two or more positions selected from the group comprising of a position in the process chamber, a position in the gas inlet pipe and a position in the gas outlet pipe, and which measure concentration of each component of the gas in the process chamber, or the concentration of each component of at least two different gases selected from the group comprising of the gas in the process chamber, the gas to be introduced into the process chamber and the gas discharged from the process chamber;
• and a control device which adjusts the components of the process gas, the concentration of each component of the process gas and an atmosphere in the process chamber, on the basis of values measured by the composition-measuring device and concentration-measuring device, such that an appropriate process is performed on the substrate.