A thermoelectric conversion material is composed of a compound semiconductor including a plurality of base material elements, and includes: an amorphous phase; and crystal phases having an average grain size of more than or equal to 5 nm, each of the crystal phases being in a form of a grain. The plurality of base material elements include a specific base material element that causes an increase of a band gap by increasing a concentration of the specific base material element. An atomic concentration of the specific base material element included in the crystal phases with respect to a whole of the plurality of base material elements included in the crystal phases is higher than an atomic concentration of the specific base material element included in the compound semiconductor with respect to a whole of the plurality of base material elements included in the compound semiconductor.