Heel unit for a ski binding, wherein the heel unit is adjustable between an engagement position, in which it engages in a heel portion of a ski boot to be coupled to the heel unit, and a release position, in which it releases the heel portion of the ski boot, and wherein the heel unit comprises: a base which has a fastening arrangement for fastening to a ski surface, a binding body which has engagement means (18a, 18b) for engagement in the heel portion of the ski boot, wherein the binding body is mounted rotatably on the base for adjustment between the engagement position and the release position of the heel unit about a vertical axis of rotation which is orthogonal to a ski plane defined by the ski surface, and an elastic element which is arranged parallel to the ski plane and orthogonal to the vertical axis of rotation and pretensions the binding body into the engagement position of the heel unit, wherein the elastic element is at least one spring, wherein the binding body comprises at least two housing parts (16a, 16b) which form a receptacle for the elastic element, wherein at least one housing part is displaceable in relation to the other housing part and a first end of the elastic element is supported directly or indirectly on a first of the two housing parts, while a second end, opposite the first end, of the elastic element is supported directly or indirectly on the other of the two housing parts (16a, 16b), characterised in that the elastic element rotates about the vertical axis of rotation together with the binding body during adjustment between the engagement position and the release position and that the elastic element extends through the vertical axis of rotation so that it protrudes on two opposite sides of the vertical axis of rotation, and that the elastic element is a spring, the spring axis of which intersects the vertical axis of rotation. a base which has a fastening arrangement for fastening to a ski surface, a binding body which has engagement means (18a, 18b) for engagement in the heel portion of the ski boot, wherein the binding body is mounted rotatably on the base for adjustment between the engagement position and the release position of the heel unit about a vertical axis of rotation which is orthogonal to a ski plane defined by the ski surface, and an elastic element which is arranged parallel to the ski plane and orthogonal to the vertical axis of rotation and pretensions the binding body into the engagement position of the heel unit, wherein the elastic element is at least one spring, wherein the binding body comprises at least two housing parts (16a, 16b) which form a receptacle for the elastic element, wherein at least one housing part is displaceable in relation to the other housing part and a first end of the elastic element is supported directly or indirectly on a first of the two housing parts, while a second end, opposite the first end, of the elastic element is supported directly or indirectly on the other of the two housing parts (16a, 16b), characterised in that the elastic element rotates about the vertical axis of rotation together with the binding body during adjustment between the engagement position and the release position and that the elastic element extends through the vertical axis of rotation so that it protrudes on two opposite sides of the vertical axis of rotation, and that the elastic element is a spring, the spring axis of which intersects the vertical axis of rotation.