Patent ID: 7637143

Claim:
A substrate processing apparatus including a housing chamber adapted to house a substrate and a gas introduction apparatus adapted to introduce gas into the housing chamber, the housing chamber including a processing space in which predetermined processing is performed on the substrate using the gas, comprising: a first gas analysis apparatus adapted to analyze gas before being introduced into the housing chamber; a second gas analysis apparatus adapted to analyze gas having passed through the processing space; and a state detection apparatus adapted to detect a state in the housing chamber based on a result of analysis on the gas before being introduced into the housing chamber and a result of analysis on the gas having passed through the processing space, wherein the state detection apparatus calculates a ratio of the result of analysis performed on the gas having passed through the processing space before execution of the predetermined processing on a plurality of the substrates to the result of analysis performed on the gas before being introduced into the housing chamber before the execution of the predetermined processing on the plurality of the substrates, calculates a ratio of the result of analysis performed on the gas having passed through the processing space after the execution of the predetermined processing on the plurality of the substrates to the result of analysis performed on the gas before being introduced into the housing chamber after the execution of the predetermined processing on the plurality of the substrates, calculates a correction value for correcting the result of analysis performed on the gas having passed through the processing space after the execution of the predetermined processing on the plurality of the substrates such that the ratio before the execution of the predetermined processing on the plurality of the substrates and the ratio after the execution of the predetermined processing on the plurality of the substrates become equal to each other, and calibrates the result of analysis on the gas having passed through the processing space using the calculated correction value.