There is provided a technique that includes (a) supplying a fluorine-containing gas to a substrate including a first surface and a second surface; (b) supplying an oxygen- and hydrogen-containing gas and a catalyst to the substrate after performing (a); (c) supplying a modifying agent to the substrate after performing (b); and (d) supplying a film-forming agent to the substrate after performing (c).

A method of manufacturing a semiconductor device includes: forming a silicon oxide film covering each of a first main surface and a second main surface of a semiconductor substrate; forming a redistribution wiring on the first main surface side of the semiconductor substrate; and grinding the second main surface of the semiconductor substrate. This grinding step is performed in a state in which a thickness of the silicon oxide film positioned on the second main surface is equal to or larger than 10 nm and equal to or smaller than 30 nm.