A prototype gas analysis system using a miniature gas chromatograph is described. The theory of gas chromatography is discussed along with silicon etching technology and miniature gas chromatography fabrication. Components of the gas analysis system including the miniature gas chromatograph and microcomputer are described, and performance capabilities are discussed. Components of the gas chromatograph are described, such as the capillary column, sample injection valve, and thermal conductivity detector. The microprocessor, solid state memory, analog to digital converter, keyboard, and display units of the microcomputer also are described. Significant capabilities of the gas analysis system that are discussed include automatic atmospheric analysis, concentration measurements, and automatic calibration of gases.