There is provided a technique which includes (a) forming a seed layer on a substrate by supplying a first process gas to the substrate at a first temperature, (b) forming a film on the seed layer by supplying a second process gas to the substrate at a second temperature, and (c) annealing the seed layer and the film at a third temperature, wherein at least one selected from the group of a crystal grain size and a surface roughness of the film after performing the annealing in (c) is adjusted by controlling a thickness of the seed layer formed in (a).