We developed an Encapsulated Production System (EPS) composed of the human space and the product space. The product space is isolated from the human space in protection from penetration of particle and gas in the human space. Concentrations of oxygen, particle, and dissolved oxygen in solutions in the product space are of 5 orders of magnitude lower than those in atmosphere. As an experimental application of the system to the control of semiconductor surface and interface, we formed Schottky barrier diodes of Al/Si(111) interface in the EPS system and investigated diode leakage currents. It was found that electrically-ideal interfaces with no leakage current and no fluctuation of Schottky barrier heights were formed in the system.