To provide a highly practical thermoelectric conversion device having an improved thermoelectric conversion efficiency.

This thermoelectric conversion device 20 comprises a wire array, wherein linear bodies 22 of a thermoelectric conversion material having a thickness corresponding to a diameter of 0.1 μm-1 μm are integrated, and an insulator 21 which has a thermal conductivity lower than that of the thermoelectric conversion material and surrounds each of the linear bodies 22. The ZT value of the thermoelectric conversion device 20 become larger, because the thermal conductivity of the linear bodies 22 of the thermoelectric conversion material is reduced under the influence of the surrounding insulator 21. The figure of merit of the thermoelectric conversion device 20 formed of a conventional thermoelectric conversion material is greatly improved by the order of several tens percent or more by only changing the manufacturing method and the structure of the thermoelectric conversion device 20.