This chapter systematically introduces bar screens, which are essential components in solid-liquid separation processes. First, it provides an overview covering their definition, uses, and recent development trends. Second, the chapter details the classification of bar screens, supplemented by tabular information for clarity. Third, it examines the structure and technical performance of various types of bar screens, including rotary, step, wire-traction, drum, curved, grab rake screen cleaners, and dry-chain (chain-driven) bar screens. Fourth, it discusses the principles and methods for selecting and calculating bar screens for different applications. Next, the chapter describes safety operation procedures and routine maintenance requirements, ensuring the reliable and long-term performance of these systems. Finally, it addresses common faults and troubleshooting techniques, equipping operators with practical knowledge for problem resolution.