A thermoelectric conversion device and a selective absorber film are provided. The thermoelectric conversion device includes at least one first selective absorber film, a cold terminal substrate, at least one first thermoelectric element pair, a first conductive substrate and a second conductive substrate. The first selective absorber film non-contactly absorbs a preset limited wavelength band of heat radiation. The first thermoelectric element pair is disposed between the first selective absorber film and the cold terminal substrate, and includes a first N-type thermoelectric element and a first P-type thermoelectric element. The first conductive substrate is disposed between the cold terminal substrate and the first N-type thermoelectric element. The second conductive substrate is disposed between the cold terminal substrate and the first P-type thermoelectric element. The first thermoelectric element pair generates current to perform power generation in response to temperature difference between the first selective absorber film and the cold terminal substrate.