A method of manufacturing a semiconductor device includes forming a layer containing a predetermined element on a substrate by supplying a source gas containing the predetermined element into a process vessel and exhausting the source gas from the process vessel to cause a chemical vapor deposition (CVD) reaction. A nitrogen-containing gas is supplied into the process vessel and then exhausted, changing the layer containing the predetermined element into a nitride layer. This process is repeated to form a nitride film on the substrate. The process vessel is purged by supplying an inert gas into the process vessel and exhausting the inert gas from the process vessel between forming the layer containing the predetermined element and changing the layer containing the predetermined element into the nitride layer.