A double-sided tangential milling cutting insert for corner milling, comprising: a first end surface, an opposed second end surface, two main side surfaces, two secondary side surfaces, a first symmetry axis passing through the first and second end surfaces (2, 3) and extending perpendicular to a reference plane dividing the cutting insert into two halves, the first and second end surfaces (2, 3) each having two diagonally opposed raised corners and two diagonally opposed lowered corners, and a through-hole penetrating the two main side surfaces and extending along a second symmetry axis, wherein the first symmetry axis and the second symmetry axis span a first symmetry plane, wherein first to fourth cutting edge sections (11a, 11b, 11c, 11d) are formed at the intersection of the first end surface with the main side surfaces and the secondary side surfaces and at the intersection of the second end surface with the main side surfaces and the secondary side surfaces, the first to fourth cutting edge sections (11a, 11b, 11c, 11d) each comprising a main cutting edge, a raised corner and a wiper edge; the wiper edge extending from the raised corner along a portion of the secondary side surface, wherein a transitional edge portion connecting the wiper edge to an adjacent lowered corner is formed along the secondary side surface, wherein adjacent to the transitional edge portion the secondary side surface has a planar support surface which comes closer to the first symmetry plane with increasing distance from the reference plane, and characterized in that the cutting insert has a third symmetry axis extending perpendicular to the first symmetry axis and to the second symmetry axis, the first symmetry axis and the third symmetry axis spanning a second symmetry plane, wherein the support surface comes closer to the first symmetry plane with increasing distance from the second symmetry plane. a first end surface, an opposed second end surface, two main side surfaces, two secondary side surfaces, a first symmetry axis passing through the first and second end surfaces (2, 3) and extending perpendicular to a reference plane dividing the cutting insert into two halves, the first and second end surfaces (2, 3) each having two diagonally opposed raised corners and two diagonally opposed lowered corners, and a through-hole penetrating the two main side surfaces and extending along a second symmetry axis, wherein the first symmetry axis and the second symmetry axis span a first symmetry plane, wherein first to fourth cutting edge sections (11a, 11b, 11c, 11d) are formed at the intersection of the first end surface with the main side surfaces and the secondary side surfaces and at the intersection of the second end surface with the main side surfaces and the secondary side surfaces, the first to fourth cutting edge sections (11a, 11b, 11c, 11d) each comprising a main cutting edge, a raised corner and a wiper edge; the wiper edge extending from the raised corner along a portion of the secondary side surface, wherein a transitional edge portion connecting the wiper edge to an adjacent lowered corner is formed along the secondary side surface, wherein the first symmetry axis and the second symmetry axis span a first symmetry plane, wherein first to fourth cutting edge sections (11a, 11b, 11c, 11d) are formed at the intersection of the first end surface with the main side surfaces and the secondary side surfaces and at the intersection of the second end surface with the main side surfaces and the secondary side surfaces, the first to fourth cutting edge sections (11a, 11b, 11c, 11d) each comprising a main cutting edge, a raised corner and a wiper edge; the wiper edge extending from the raised corner along a portion of the secondary side surface, wherein a transitional edge portion connecting the wiper edge to an adjacent lowered corner is formed along the secondary side surface, wherein adjacent to the transitional edge portion the secondary side surface has a planar support surface which comes closer to the first symmetry plane with increasing distance from the reference plane, and characterized in that the cutting insert has a third symmetry axis extending perpendicular to the first symmetry axis and to the second symmetry axis, the first symmetry axis and the third symmetry axis spanning a second symmetry plane, wherein the support surface comes closer to the first symmetry plane with increasing distance from the second symmetry plane.