There is provided a method for manufacturing a semiconductor device, including forming a film on a substrate by performing a cycle one or more times. The cycle includes forming a first layer containing silicon, nitrogen, and carbon by supplying a first silane-based source having a halogen-based ligand to the substrate and supplying a second silane-based source having amino groups to the substrate. The cycle also includes forming a second layer by modifying the first layer by performing supplying a reactive gas different from each of the sources, to the substrate.