Abstract: A thermoelectric generator using catalytic combustion heat of fuel gas as a heat source, has a construction wherein a thermoelectric element or a planar electric generation unit comprising thermoelectric elements has a construction held between the thermal input part and the heat radiation part, having fuel gas supply means and means for mixing fuel gas with air, and having a structure such that the combustion heat can be directly supplied to the thermoelectric element by burning the mixed gas of fuel with air in a catalyst part arranged in the thermal input part, the thermal input part having a heat conductive end plate and a catalyst part which are in contact with the thermoelectric element, the face opposite to the thermoelectric element of the heat conductive end plate having a structure of convex and concave configuration, and the catalyst part being constituted in the convex and concave configuration surface.