The method of manufacturing the thermoelectric material including a plurality of phases that are phase-separated from a supersaturated solid solution includes: a process of performing a mechanical alloying treatment to a starting raw material that is prepared with a composition deviated from a composition range existing in an equilibrium state of a compound to generate the supersaturated solid solution; and a process of performing phase separation into the plurality of phases and solidification by heating and pressing the supersaturated solid solution, or by further performing a heat treatment according to the circumstances.