Polymeric Micro-Fabricated Filters Have Excellent Sieving Properties. Their Identical Properties such as High Surface Porosity and Perfectly Patterned Pore Structure, which Is Combined with Mechanical Strength Make them Ideal for many Applications such as Microorganism Removal, Blood Filtration and Protein Purification. To Improve the Performance of the Micro-Fabricated Filters, we Employed Oxygen Plasma Treatment to Increase the Surface Hydrophilicity and Reduce the Membrane Fouling during Microfiltration. Hydrophilization and Integrity of the Surfaces Were Analyzed by Contact Angle Measurements and Topographic Imaging with an Atomic Force Microscope (AFM). Treatment of Polymeric Membranes with Oxygen Plasma Led to a Stable Hydrophilization and an Increased Surface Roughness. The Filtration Properties of the Modified and Unmodified Membranes Were Examined Using Clay Particles. A Significant Increase in Total Collected Volume of Filtrate Was Observed for the Treated Membranes during Filtration of Simulated Drinking Water Samples Using Clay Suspension.