A left atrial appendage closure device comprises two clamping jaws (2) fixed to a bow (3) comprising a flange with a cut slot, where each of the edges of the slot is connected with the clamping jaw (2). The jaws (2) contain internal channels (5). In a section perpendicular to the symmetry axes of the internal channels (5), a line (a) connecting the symmetry axes of the internal channels (5) is distant from an imaginary line (b) connecting the centres of sections of the bow (3) arms by a distance (14). The bow (3) has in the central part of its periphery a larger section (6) than a section (7) in the places where the bow (3) arms are connected with the jaws (2). The jaw (2) wall (9) from the adjacent jaw (2) side is the thinnest, whereas the wall (9) from the side of fixing the clamping jaw (2) to the bow (3) is the thickest.
