A thermoelectric power-generation device comprising: a first flow path through which a first fluid flows; a second flow path through which a second fluid that has a temperature difference with respect to the first fluid flows; an insulating isolation plate configured to isolate the first flow path from the second flow path; insulating outer layer isolation plates provided at outermost portions of layered flow paths including the first flow path and the second flow path; a plurality of thermoelectric conversion units (30, 40) configured to generate power using the temperature difference; and electrodes provided at the insulating outer layer isolation plates and configured to connect the thermoelectric conversion units (30, 40) with mutually different semiconductor polarities in series, wherein the plurality of thermoelectric conversion units (30, 40) are disposed so as to straddle the first flow path and the second flow path, the plurality of thermoelectric conversion units (30, 40) include conductive members (31, 41) configured to extend into and block through-holes formed in the insulating isolation plate, first thermoelectric conversion elements disposed at the first flow path and connected to the conductive members (31, 41), and second thermoelectric conversion elements disposed at the second flow path, the first and second thermoelectric conversion elements (32, 42) being connected to the conductive members (31, 41), and having same sectional shapes as the conductive members (31, 41), and the first thermoelectric conversion elements and the second thermoelectric conversion elements have a mutually same semiconductor polarity. a first flow path through which a first fluid flows; a second flow path through which a second fluid that has a temperature difference with respect to the first fluid flows; an insulating isolation plate configured to isolate the first flow path from the second flow path; insulating outer layer isolation plates provided at outermost portions of layered flow paths including the first flow path and the second flow path; a plurality of thermoelectric conversion units (30, 40) configured to generate power using the temperature difference; and electrodes provided at the insulating outer layer isolation plates and configured to connect the thermoelectric conversion units (30, 40) with mutually different semiconductor polarities in series, wherein the plurality of thermoelectric conversion units (30, 40) are disposed so as to straddle the first flow path and the second flow path, the plurality of thermoelectric conversion units (30, 40) include conductive members (31, 41) configured to extend into and block through-holes formed in the insulating isolation plate, first thermoelectric conversion elements disposed at the first flow path and connected to the conductive members (31, 41), and second thermoelectric conversion elements disposed at the second flow path, the first and second thermoelectric conversion elements (32, 42) being connected to the conductive members (31, 41), and having same sectional shapes as the conductive members (31, 41), and the first thermoelectric conversion elements and the second thermoelectric conversion elements have a mutually same semiconductor polarity.