This study focused on developing a new membrane type by incorporating magnetic iron oxide nanoparticles (Fe3O4) into a polyethersulfone (PES) matrix to create a Fe3O4/PES membrane. The synthesized membrane was characterized using various techniques, including SEM, Map, 3D images, TEM, XRD, and FT-IR, to determine its structure and properties. The membrane's performance was evaluated by examining parameters such as water contact angle, membrane pore size and porosity, water content, Pure Water Flux (PWF), and salt rejection. The results showed that the Fe3O4/PES membrane outperformed the pure PES membrane regarding water flux and salt rejection. The membrane with a Fe3O4 concentration of 0.01wt.% had the highest flux value of 16.35 (L/m2h), while the virgin membrane's flux value was only 2.81 (L/m2h). Furthermore, the salt rejection of the modified membrane increased from 60% to 90% compared to the pure PES membrane. It was observed that the Fe3O4 nanoparticles, which had a positive charge of 3-7 nm, tended to agglomerate and increase in size when the Fe3O4 concentration was increased, leading to a negative surface charge. By using fewer Fe3O4 nanoparticles, the Fe3O4/PES membrane achieved similar performance as other research, making it a more cost-effective option.