The purpose of this chapter is to provide an understanding of the state-of-the-art control of air pollutants from stationary sources for both particulate and gaseous emissions. It begins by providing an understanding of the nature of air quality concerns associated with fugitive emissions and their control, followed by stressing the importance of pollution prevention principles in reducing, or eliminating air pollution emissions prior to their being formed and emitted from sources. These principles include fuel substitution, process equipment changes, plant operating practices, process changes, and energy conservation, among others. This chapter then provides an understanding of collection efficiency differences associated with particle/dust cleaning equipment; a familiarity with the use, operating principles, and limitations and advantages of cyclonic dust collectors, fabric filtration, electrostatic precipitation, and wet scrubbers for particle/dust collection; and an understanding of the differences between control systems for particle/dust collection and control systems for gaseous pollutants. This chapter then transitions to gaseous pollution control technologies and provides understanding of principles, applications, and limitations of thermal oxidation, adsorption, and absorption/scrubbing control systems; biological treatment systems, their use, and limitations; principles and practices employed in wet and dry flue gas desulfurization processes; and familiarity with NOx control techniques as applied to EGU and industrial boilers. For the first time, this chapter includes new sections that familiarize the reader with emerging technologies being proposed and used to control CO2 emissions from stationary sources as well as emerging stationary technologies being proposed and used to capture CO2 from the ambient air.