Ceramic membranes composed of fly ash-clay have been fabricated by using a sintering method at low temperatures. The membranes were made with a variety of fly ash composition of clay 35%: 65%(M1), 45%: 55%(M2), 50%: 50%(M3), 55%: 45%(M4), 65%: 35%(M5) at sintering temperatures of 900 C and 1000 C. The pore sizes, crystal structures, and membrane composition were analyzed by Scanning Electron Microscopy (SEM) and energy-dispersive X-ray (EDX), while the membrane phase composition was analyzed by X-Ray Diffraction (XRD). The SEM-data showed that the M5 membrane sintered at 1000 C was classified as a microfiltration (MF) membrane with an average pore size of 0.6 µm. Based on the analysis using the X-Ray diffraction (XRD), the crystal structure of the membrane was dominated by the quartz phase (SiO2) and illite ((KH3O) Al2Si3AlO10 (OH) 2). It was also confirmed with EDX that the material is dominated by O, Si, and Al elements.