Described herein is a technique capable of suppressing generation of particles by removing by-products in a groove of a high aspect ratio. According to one aspect of the technique, there is provided a substrate processing apparatus including: a process chamber in which a substrate is processed; and a substrate support provided in the process chamber and including a plurality of supports where the substrate is placed, wherein the process chamber includes a process region where a process gas is supplied to the substrate and a purge region where the process gas above the substrate is purged, and the purge region includes a first pressure purge region to be purged at a first pressure and a second pressure purge region to be purged at a second pressure higher than the first pressure.