An n-type thermoelectric conversion material expressed in a chemical formula X3-xX′xT3-yCuySb4 (0≦x 0), the X includes one or more element(s) of Zr and Hf, the X′ includes one or more element(s) of Nb and Ta, and the T includes one or more element(s) selected from Ni, Pd, and Pt, while including at least Ni, the n-type thermoelectric conversion material expressed in the chemical formula X3-xX′xT3-yCuySb4 has symmetry of a cubic crystal belonging to a space group I-43d.