Abstract: In a substrate processing method, a rinse process using a rinse solution is performed on a development-processed photoresist pattern on a substrate. A substitution process including a first substitution step using a mixed solution of a non-polar organic solvent and a surfactant and a second substitution step using the non-polar organic solvent is performed on the substrate. The substitution process is performed a plurality of times until the rinse solution remaining on the substrate is less than a predetermined value. A supercritical fluid drying process is performed on the substrate to dry the non-polar organic solvent remaining on the substrate.