Method of manufacturing semiconductor device

A method of manufacturing a semiconductor device, comprising:

• (a) loading a substrate having a hole into a transfer space via a substrate loading/unloading port;
• (b) moving the substrate to a processing space;
• (c) forming a precursor in the hole by simultaneously supplying a first process gas to the substrate in the processing space and an inert gas into the transfer space with the processing space spatially connected to the transfer space and maintaining a difference between a first inner pressure of the processing space and a first inner pressure of the transfer space within a predetermined range;
• and
• (d) forming a thin film in the hole after performing (b) by modifying the precursor by supplying a second process gas to the substrate in the processing space and the inert gas into the transfer space with the processing space spatially connected to the transfer space and maintaining a difference between a second inner pressure of the processing space and a second inner pressure of the transfer space within a predetermined range, wherein the second inner pressure of the processing space is higher than the first inner pressure of the processing space.