Publisher Summary This chapter presents a review of the representative current vacuum practice in the electronics industry. Developments in pumping equipment are considered specifically in relation to their application in today's accelerated production techniques. The data on the commercially available pumps have been compiled from information furnished by the manufacturers. Pressure measurements are expressed in millimeters or microns relative to a mercury column that is raised to the height of 760 mm by one standard atmosphere. Measurements are made by gauges that observe the pressure by different means and transfer the reading to a scale. In the case of mechanical pumps, the McLeod gauge is used, except where otherwise specified; in the case of vapor pumps, ionization gauges are used.