A micro-porous filtration membrane which is a multi-layer membrane, comprising at least two different membrane layers having different pore sizes such that a first membrane layer on the non-filtrate side in terms of a pre-filter made of a micro-porous matrix material has a larger pore size compared to a second membrane layer on the filtrate side in terms of an end-filter made of a micro-porous matrix material, wherein at least one membrane layer comprises a plurality of three-dimensional projections extending from a second main surface on the filtrate side of the membrane, wherein the three-dimensional projections are formed by stamping from a first main surface on the non-filtrate side of the at least one membrane layer opposite to the second main surface of the at least one membrane layer upon which corresponding recesses are formed on the first main surface, wherein the three-dimensional projection on the second main surface of the at least one membrane layer is the negative stamping shape of the positive stamping shape of the three-dimensional projection stamped from the first main surface of the at least one membrane layer, said stamping is carried out by using a stamping device including a positive stamp and a negative stamp upon application of a pressure of approximately 1.0 to 1.5 bar, wherein the form of the positive stamp corresponds to the shape of the recesses to be formed and the form of the negative stamp corresponds to the shape of the projections to be formed, wherein upon forming the three-dimensional projections, the micro-porous structure of the material constituting the at least one membrane layer is substantially not compressed, so as to maintain the micro-porous structure, and wherein in case the at least one membrane layer having the plurality of three-dimensional projections is provided as the pre-filter, the three-dimensional projections act as spacers between the pre-filter layer and the end-filter layer, or in case the at least one membrane layer having the plurality of three-dimensional projections is provided as the end-filter, the recesses function as macroscopic cavities within the micro-porous filtration membrane, so that the filtrate side surface of the pre-filter does not entirely cover the surface of the end-filter on its non-filtrate side. wherein at least one membrane layer comprises a plurality of three-dimensional projections extending from a second main surface on the filtrate side of the membrane, wherein the three-dimensional projections are formed by stamping from a first main surface on the non-filtrate side of the at least one membrane layer opposite to the second main surface of the at least one membrane layer upon which corresponding recesses are formed on the first main surface, wherein the three-dimensional projection on the second main surface of the at least one membrane layer is the negative stamping shape of the positive stamping shape of the three-dimensional projection stamped from the first main surface of the at least one membrane layer, said stamping is carried out by using a stamping device including a positive stamp and a negative stamp upon application of a pressure of approximately 1.0 to 1.5 bar, wherein the form of the positive stamp corresponds to the shape of the recesses to be formed and the form of the negative stamp corresponds to the shape of the projections to be formed, wherein upon forming the three-dimensional projections, the micro-porous structure of the material constituting the at least one membrane layer is substantially not compressed, so as to maintain the micro-porous structure, and wherein in case the at least one membrane layer having the plurality of three-dimensional projections is provided as the pre-filter, the three-dimensional projections act as spacers between the pre-filter layer and the end-filter layer, or in case the at least one membrane layer having the plurality of three-dimensional projections is provided as the end-filter, the recesses function as macroscopic cavities within the micro-porous filtration membrane, so that the filtrate side surface of the pre-filter does not entirely cover the surface of the end-filter on its non-filtrate side.