A thermoelectrically active p- or n-conductive semiconductor material is constituted by a ternary compound of the general formula (I) (Pb.sub.1-xGe.sub.x)Te (I) with x value from 0.16 to 0.5, wherein 0 to 10% by weight of the ternary compound may be replaced by other metals or metal compounds, wherein the semiconductor material has a Seebeck coefficient of at least .+-.200 .mu.V/K at a temperature of 25.degree. C.