Faced with water shortages and the need to recycle wastewater, ceramic membranes stand out as an efficient, environmentally friendly solution for filtration. Although their manufacturing cost is relatively high, the use of clay, an abundant and inexpensive material, reduces these costs. This chapter examines the importance of flat clay-based ceramic membranes, highlighting their durability and cost-effectiveness. The chapter covers membrane-manufacturing steps, including raw material conditioning, powder preparation, shaping, and heat treatment or sintering. It highlights the incorporation of pore-forming agents to improve membrane porosity and permeability. All in all, the use of clay makes it possible to manufacture cost-effective, high-performance ceramic membranes tailored to today’s water treatment needs.