A thermoelectric conversion material has a composition represented by the chemical formula Li3-aBi1-bGeb, in which the range of values a and b is: 0≤a≤0.0003, and −a+0.0003≤b≤0.108; 0.0003≤a≤0.003, and 0≤b≤0.108; or 0.003≤a≤0.085, and 0≤b≤exp[−0.157×(ln(a))2−2.22×ln(a)−9.81], and in which the thermoelectric conversion material has a BiF3-type crystal structure and has a p-type polarity.