The invention relates to a membrane implant for treating vascular malformations, for the endovascular implantation into the vessel to be treated, the membrane implant consisting of an expandable stent (4) and a membrane (2, 3, 5, 11) connected to the stent (4). Said membrane (2, 3, 5, 11) covers mesh of the stent (4) at least in a center region and is designed as a non-woven fabric that contains synthetic filaments. The membrane (2, 3, 5, 11) is integrally connected to the stent (4) and is porous in at least some sections.