A thermal plate of a PEB unit is divided into a plurality of thermal plate regions, and a temperature is settable for each of the thermal plate regions. A temperature correction value for adjusting the temperature within the thermal plate is settable for each of the thermal plate regions of the thermal plate. The line widths within the substrate for which a photolithography process has been finished are measured. The in-plane tendency of the measured line widths is decomposed into a plurality of in-plane tendency components using a Zernike polynomial. Then, in-plane tendency components improvable by setting the temperature correction values are extracted from the calculated plurality of in-plane tendency components and added to calculate an improvable in-plane tendency in the measured line widths. Then, the improvable in-plane tendency is subtracted from the in-plane tendency Z of the current processing states to calculate an after-improvement in-plane tendency.