This study attempts to research and develop the process of the microwave components with narrowband bandpass filter, and establish the relative data between production process and electrial characteristics of communication, to improve the defect during production, and upgrade the yield of product. The content of this study method mainly concerns about the discussion on precision drilling problem of 38GHz microwave element. Through precision measurement, to understand the drilling quality, and aid with MC(Machining Center) in high speed spindle to perform drilling , and uses Taguchi table to plan this experiment, the idea of matter element, relational function etc. in Extention set, can be develop and prode into the optimal coefficient. expecting to improve the roundness, squareness, surface roughness, etc.ito upgrade the electrical characteristics of microwave element, and reduce the nonconforming proportion of product.