This chapter focuses on the use of membrane systems for particle removal from process chemicals. Process chemicals are generally filtered by the chemical manufacturers to semiconductor industry standards as set by semiconductor equipment manufacturing institute. These chemicals are then refiltered prior to use, either as part of a continuously recirculating chemical bath or as part of the chemical supply system. The chapter reviews the various steps used in the manufacture of large-scale integrated circuits including the different chemical reagents used in these processes. The microelectronics industry began with the development of the transistor in the late 1940s. The integrated circuit exploits the unique electronic attributes of silicon. Membrane microfiltration and/or ultrafiltration are used to filter essentially all gases, liquids, and deionized water used in microelectronics manufacturing. One of the primary considerations in the design of a membrane system for microelectronics applications is the need for chemical compatibility of the membranes, support materials, seals, O-rings, and housing materials.