Described herein is a technique capable of forming a film so as to fill a recess of a substrate. According to one aspect thereof, there is provided a substrate processing apparatus including: a substrate mounting table on which a substrate is placed; an adsorption inhibiting gas supplier configured to supply an adsorption inhibiting gas onto a surface of the substrate from above the substrate mounting table; and a source gas supplier configured to supply a source gas onto the surface of the substrate from above the substrate mounting table, wherein a distance D1 between a gas supply port provided in the adsorption inhibiting gas supplier and the substrate is greater than a distance D2 between a gas supply port provided in the source gas supplier and the substrate.