This chapter presents an in-depth introduction to air flotation equipment utilized in water and wastewater treatment. Firstly, it explains the fundamental principles of air flotation, including definitions, primary applications, and the development trends both in China and abroad. Secondly, the chapter discusses the classification of flotation methods to provide a framework for understanding the various systems in use. Thirdly, it examines electro-flotation equipment in detail, describing its general structure, horizontal flow design, and distinctive features. Fourthly, the focus shifts to diffused air flotation equipment, specifically covering both jet and impeller aerators. Fifthly, dissolved air flotation equipment is analyzed, addressing pressurized and vacuum systems as well as key operational characteristics. The chapter then introduces new flotation technologies, such as surface aerators and cavitation air flotation equipment. Finally, it highlights safe operating procedures and offers guidance on common faults and troubleshooting.