Thermoelectric material is produced through a process sequence including a liquid quenching, a primary solidification such as a hot pressing or extrusion and an upset forging; although the C-planes of the crystal grains are directed in parallel to the direction in which the force is exerted on flakes during the hot pressing/extrusion, the a-axes are randomly directed; the a-axes are oriented in a predetermined direction through the upset forging; this results in improvement of electric resistivity without reduction in the figure of merit.