Abstract: An apparatus for processing a substrate by supplying a processing gas to the substrate in a processing container. The apparatus comprises: a mounting table provided in the processing container and for mounting the substrate; a gas shower head comprising a gas diffusion space provided at a position facing the mounting table and for diffusing the processing gas, and a shower plate having a plurality of gas supply holes for supplying the processing gas diffused in the gas diffusion space to the processing container; a gas supply portion provided to supply the processing gas to the gas diffusion space and having a flow rate adjusting portion for the processing gas; a pressure sensor portion provided in the gas diffusion space and to output a pressure signal corresponding to a pressure measurement value in the gas diffusion space; and a controller to output a control signal for adjusting a flow rate of the processing gas.

Abstract: An OES measuring unit outputs a spectroscopically measured value for each step at the end of or immediately after each step. A CD estimating unit obtains an estimated CD value for each step using a CD estimation model and a spectroscopically measured value received from an estimation model storage unit.