There is provided a technique that includes forming a film in a concave portion provided on a surface of a substrate by performing a cycle a predetermined number of times, the cycle including: (a) forming an adsorption inhibition layer by supplying an adsorption inhibitor, which inhibits adsorption of a precursor, to the substrate and adsorbing the adsorption inhibitor on adsorption sites of an upper portion in the concave portion; (b) forming a first layer by supplying the precursor to the substrate and adsorbing the precursor on adsorption sites existing in the concave portion in which the adsorption inhibition layer is formed; and (c) modifying the adsorption inhibition layer and the first layer into a second layer by supplying a first reactant, which chemically reacts with both the adsorption inhibition layer and the first layer, to the substrate.