Disclosed is a substrate processing system capable of performing an etching processing collectively on a plurality of substrates accommodated in a processing container. The system includes: a first acquisition unit which acquires, as information, an amount of a film forming material formed on one of the substrates; a second acquisition unit which acquires, as information, the number of the substrates; a first calculating unit which calculates a total amount of the film forming material formed on the substrates based on the amount of the film forming material and the number of the substrates; and a second calculating unit which calculates an etching condition required to etch and remove the entire film forming material based on the total amount of the film forming materials and a relationship between a predetermined amount of the film forming material and an etching condition.