Method of manufacturing semiconductor device, substrate processing apparatus, and recording medium

A method of manufacturing a semiconductor device, comprising:

• forming an initial layer including a layer composed of a predetermined element and at least one of a nitride layer and an oxynitride layer, the initial layer having a thickness greater than or equal to two atomic layers and less than or equal to six atomic layers on a substrate in a process chamber by supplying a predetermined-element-containing gas to the substrate;
• and
• forming an oxide film including the predetermined element on the initial layer by performing a cycle a predetermined number of times, the cycle comprising supplying a precursor gas including the predetermined element to the substrate in the process chamber and supplying an oxygen-containing gas and a hydrogen-containing gas to the substrate heated in the process chamber under a pressure lower than an atmospheric pressure,
• wherein the initial layer serves as a layer for preventing oxidation of a surface of the substrate during the forming of the oxide film.