There is provided a technique that includes forming a film containing silicon, oxygen, carbon, and nitrogen on a substrate by performing a cycle a predetermined number of times, the cycle including: forming a first layer containing silicon, carbon, and nitrogen by performing a set a predetermined number of times, the set including: supplying a first precursor, which contains at least two Si—N bonds and at least one Si—C bond in one molecule, to the substrate; and supplying a second precursor, which contains nitrogen and hydrogen, to the substrate; and forming a second layer by supplying an oxidant to the substrate, to thereby oxidize the first layer.