Disclosed is a substrate processing method that dissolves and deforms a photoresist film having a first pattern formed on a substrate to reshape the resist film into a second pattern. The method includes: evacuating a processing chamber, thereby reducing an internal pressure of the processing chamber from a standard pressure to a first target pressure lower than the standard pressure; introducing a solvent vapor-containing atmosphere into the processing chamber, thereby bringing the internal pressure back to the standard pressure; dissolving the resist film by a solvent contained in the solvent vapor-containing atmosphere; and evacuating a processing chamber, thereby reducing the internal pressure to a second target pressure higher than the first target pressure and lower than the standard pressure and discharging the solvent vapor-containing atmosphere from the processing chamber. Owing to the relatively low second target pressure, undesirable deformation of the resist film or defects in the resist film due to rapid evaporation of the solvent penetrated in the resist film can be prevented.