In this theoretical study, a design and performance analysis theory of a micro flowrate and high pressure air-compressor is developed. The governing equations are from the gas state equation and fluid dynamic theories because the working fluid in the air compressor is in a gas phase. A case study was conducted to design a reciprocating type of air compressor which the target performance was 0.6liter/min in the volume flowrate with 5atg in air pressure at 1,600rpm rotational speed. Geometrical size of the model air compressor designed is 10mm in stroke, 20mm in bore with 4.79 compression ratio. From the performance analysis of the model compressor, it was found that the air volume flowrate produced was 0.6liter/min with 5.81atg in pressure. The design theory of a micro-size high-pressure air compressor developed in this study is expected to be very useful design tools in NANO technology industry.