In this study, novel diamond porous membranes are developed through a reliable process providing a unique pathway toward large surface area and porous materials. Mainly deposited onto flat surface so far, we demonstrate here that diamond coating is possible on very complex 3D shapes, even nanoporous ones, through an original nanoseeding process and adapted growth conditions. Such membranes or filters exhibit outstanding features thanks to the unique mechanical properties and surface chemistry of diamond. Indeed, the straightforward tuning of their surface properties associated to their high stability ensures the diamond porous membranes' applications in the scope of filtration, separation and extraction. Preliminary electrochemical studies highlight the membranes' potential to be used for high specific area electrode applications. After an extensive characterization of these new diamond porous membranes, their potential for protein extraction will be demonstrated through mass spectrometry detection.