There is provided a technique that includes: a process vessel in which a substrate is accommodated and processed; a plasma generator configured to generate a plasma in the process vessel; a calculator configured to calculate a cumulative amount of an electric power output by the plasma generator during a processing of the substrate; a memory configured to store, as a master cumulative amount, the cumulative amount at an end of the processing of the substrate when a result of the processing of the substrate is normal; and a controller configured to be capable of controlling a progress of the processing of the substrate based on a recipe defining process conditions containing a process time for the substrate, and capable of calculating a correction time for the process time from a difference between the cumulative amount calculated by the calculator and the master cumulative amount.