A thermoelectric leg comprising: a thermoelectric material layer including Bi and Te; a first metal layer and a second metal layer respectively disposed on one surface of the thermoelectric material layer and the other surface thereof; a first bonding layer interposed between the thermoelectric material layer and the first metal layer and including Te; a second bonding layer interposed between the thermoelectric material layer and the second metal layer and including Te; a first plated layer interposed between the first metal layer and the first bonding layer; and a second plated layer interposed between the second metal layer and the second bonding layer, wherein the thermoelectric material layer is interposed between the first metal layer and the second metal layer, a content of the Te is higher than a content of the Bi from a centerline of the thermoelectric material layer to an interface between the thermoelectric material layer and the first bonding layer, a content of the Te is higher than a content of the Bi from the centerline of the thermoelectric material layer to an interface between the thermoelectric material layer and the second bonding layer, characterised in that a content of the Te at a predetermined position between the centerline of the thermoelectric material layer and the interface between the thermoelectric material layer and the first bonding layer is in a range of 0.8 to 1 times a content of the Te at the centerline of the thermoelectric material layer, wherein a content of the Bi of an interface between the thermoelectric material layer and the first bonding layer is in a range of 0.8 to 1 times a content of the Bi at the centerline of the thermoelectric material layer, and wherein a content of the Bi of an interface between the thermoelectric material layer and the second bonding layer is in a range of 0.8 to 1 times a content of the Bi at the centerline of the thermoelectric material layer. a thermoelectric material layer including Bi and Te; a first metal layer and a second metal layer respectively disposed on one surface of the thermoelectric material layer and the other surface thereof; a first bonding layer interposed between the thermoelectric material layer and the first metal layer and including Te; a second bonding layer interposed between the thermoelectric material layer and the second metal layer and including Te; a first plated layer interposed between the first metal layer and the first bonding layer; and a second plated layer interposed between the second metal layer and the second bonding layer, wherein the thermoelectric material layer is interposed between the first metal layer and the second metal layer, a content of the Te is higher than a content of the Bi from a centerline of the thermoelectric material layer to an interface between the thermoelectric material layer and the first bonding layer, a content of the Te is higher than a content of the Bi from the centerline of the thermoelectric material layer to an interface between the thermoelectric material layer and the second bonding layer, characterised in that a content of the Te at a predetermined position between the centerline of the thermoelectric material layer and the interface between the thermoelectric material layer and the first bonding layer is in a range of 0.8 to 1 times a content of the Te at the centerline of the thermoelectric material layer, wherein a content of the Bi of an interface between the thermoelectric material layer and the first bonding layer is in a range of 0.8 to 1 times a content of the Bi at the centerline of the thermoelectric material layer, and wherein a content of the Bi of an interface between the thermoelectric material layer and the second bonding layer is in a range of 0.8 to 1 times a content of the Bi at the centerline of the thermoelectric material layer.