Chronic Kidney Disease (CKD) is a condition where the kidney does not work well anymore. It makes the metabolic waste and water are no longer excluded from the body. In a certain condition, those waste can poison the body and cause a mortality. Therefore, the patient must do a hemodialysis every week by using dialyzer. Considering the background above, Gu and Miki have developed Wearable Artificial Kidney (WAK) based on micro filter by using structural layers that was made by stainless steel SS316L material served as micro chamber by using semipermeable membrane as the filtration media for replacing the function of kidney. This study was done to determine the ratio of each fabric membrane that had high permeability value or known as water flux by using phase inversion method. In addition, the basic material of the membrane was using Polyethersulfone (PES), Polyethylene glycol (PEG) as the addictive substances and N-Dimethylacetamide (DMAc) as the solvent media. The gelatinization media was using two variations such as akuades with the addition of 2%, 4%, 6%, 8% NMP and akuades without the addition of N-Methy1-2-Pyrrolidone (NMP). The diffusion test found the membrane that had a high permeability value were gained from the variation of gelatinization media with the addition of 8% NMP that had a water flux 871.8 (ml/m²/mmHg), diffusion coefficient value of 0.07(mm²/s). Moreover, the value of water contact angle was inversely by 56º. For the low permeability value was showed from the membrane with the gelatinization media of 4% NMP that had a water flux value 186.8 (ml/m²/mmHg), diffusion coefficient of 0.06 (mm²/s) and water contact angle of 78º. The more permeability a certain membrane is closely related to a membrane morphology like the diameter size of pores formed, pores uniformity, and the thickness of the membrane itself.