A thermoelectric generator includes a perovskite dielectric substrate containing Sr and Ti and having electric conductivity by being doped to n-type; an energy filter formed on a top surface of the perovskite dielectric substrate, the energy filter including a first perovskite dielectric film, which contains Sr and Ti, has electric conductivity by being doped to n-type, and has a conduction band at an energy level higher than that of the perovskite dielectric substrate; a first electrode formed in electrical contact with a bottom surface of the perovskite dielectric substrate; and a second electrode formed in electrical contact with a top surface of the energy filter. The thermoelectric generator produces a voltage between the first and second electrodes by the top surface of the energy filter being exposed to a first temperature and the bottom surface of the perovskite dielectric substrate being exposed to a second temperature.