A throughput in processing a substrate can be improved and a running cost thereof can be reduced. A substrate processing apparatus 1 that processes a substrate 3 with a processing liquid and dries the substrate 3 includes a substrate rotating device 22 configured to rotate the substrate 3; a processing liquid discharging unit 13 configured to discharge the processing liquid toward the substrate 3; a substitution liquid discharging unit 14 configured to discharge a substitution liquid, which is substituted with the processing liquid on the substrate 3, toward the substrate 3 while relatively moving with respect to the substrate 3; and an inert gas discharging unit 15 configured to discharge an inert gas toward a peripheral portion of the substrate 3 in an inclined direction from above the substrate 3 while moving in a direction different from a direction in which the substitution liquid discharging unit 14 is moved.