An evacuated sheet material (1;1';1") for thermal insulation, comprising a) at least one flat core (2;2';2") made of an open-pored material and having two main surfaces extending approximately parallel to each other and a fully circumferential perimeter region connecting the two main surfaces to each other, b) a first barrier film (8;8';8") that is in large-area contact with a first main surface of the core and comprises at least one sealing layer facing the core (2;2';2"), as well as a fully circumferential protrusion of said first barrier film (8;8';8") with respect to the first main surface of the core (2;2';2"), c) a flat filter material (11;11';11") that is in large-area contact with the opposite main surface of the open-pored core (2;2';2") from the first barrier film (8;8';8") and presents a fully circumferential protrusion with respect to the second main surface of the core (2;2';2"), d) a second barrier film (13;13';13") that is in large-area contact with the outer face of the flat filter material (11;11';11") and comprises a sealing layer facing said flat filter material (11;11';11"), as well as a fully circumferential protrusion of said second barrier film (13;13';13") with respect to the second main surface of the core (2;2';2"), e) a sealing seam (15;15';15") that extends fully circumferentially along the common protrusion of the two barrier films (8,13;8',13';8",13") and fixes the two barrier films (8,13;8',13';8",13") to each other, f) wherein said filter material (11;11';11") is welded fully circumferentially into the sealing seam (15;15';15") between the two barrier films (8,13;8',13',8",13"), g) and wherein the volume between the two barrier films (8,13;8',13',8",13") and the fully circumferential sealing seam (15;15';15"), consisting of the open-pored core (2;2';2") and the inner portion of the filter material (11;11';11"), is sealed vacuum-tightly and evacuated. a) at least one flat core (2;2';2") made of an open-pored material and having two main surfaces extending approximately parallel to each other and a fully circumferential perimeter region connecting the two main surfaces to each other, b) a first barrier film (8;8';8") that is in large-area contact with a first main surface of the core and comprises at least one sealing layer facing the core (2;2';2"), as well as a fully circumferential protrusion of said first barrier film (8;8';8") with respect to the first main surface of the core (2;2';2"), c) a flat filter material (11;11';11") that is in large-area contact with the opposite main surface of the open-pored core (2;2';2") from the first barrier film (8;8';8") and presents a fully circumferential protrusion with respect to the second main surface of the core (2;2';2"), d) a second barrier film (13;13';13") that is in large-area contact with the outer face of the flat filter material (11;11';11") and comprises a sealing layer facing said flat filter material (11;11';11"), as well as a fully circumferential protrusion of said second barrier film (13;13';13") with respect to the second main surface of the core (2;2';2"), e) a sealing seam (15;15';15") that extends fully circumferentially along the common protrusion of the two barrier films (8,13;8',13';8",13") and fixes the two barrier films (8,13;8',13';8",13") to each other, f) wherein said filter material (11;11';11") is welded fully circumferentially into the sealing seam (15;15';15") between the two barrier films (8,13;8',13',8",13"), g) and wherein the volume between the two barrier films (8,13;8',13',8",13") and the fully circumferential sealing seam (15;15';15"), consisting of the open-pored core (2;2';2") and the inner portion of the filter material (11;11';11"), is sealed vacuum-tightly and evacuated.