Patent ID: 8364422

Claim:
A method of presuming interior situation of process chamber that presumes an interior situation of a process chamber in which a substrate is accommodated and subjected to predetermined processing and to which a particle removing sequence comprising a plurality of particle removing modes is applied, the method being carried out by an apparatus that is comprised of a computer programmed to perform the method and to presume an interior situation of the process chamber, comprising: a characteristic value extracting step of extracting a plurality of characteristic values associated with the respective particle removing modes based on the interior situation of the process chamber in each of the plurality of the particle removing modes and time-series data on a number of particles discharged from the interior of the process chamber; and an interior situation presuming step of presuming the interior situation of the process chamber by calculating a presumed value of a number of particles on the substrate based on each of the plurality of characteristic values in new time-series data on the number of particles and by integrating each of the calculated presumed values of the number of particles on the substrate in consideration of statistical reliability of a relationship between each of the characteristic values and the number of the particles on the substrate, wherein the plurality of characteristic values are the number of times the time-series data exceeds a predetermined threshold value, a time at which the time-series data exceeds the predetermined threshold value for the first time, a time at which the time-series data last becomes smaller than the predetermined threshold value, and an integrated time period for which the time-series data exceeds the predetermined threshold value.