Abstract: A thermoelectric power generation device includes a plurality of units that are stacked, each unit including a thermoelectric module containing at least one thermoelectric element, and a first plate and a second plate interposing the thermoelectric module therebetween, wherein a spacer is interposed between a surface of one of the first plates facing away from the corresponding thermoelectric module and a surface of the opposing second plate facing away from the corresponding thermoelectric module, the spacer contacting the first plate and the second plate and defining a fluid passage jointly with the first plate and the second plate, and wherein the fluid passages defined between the adjacent units are configured to receive supply of high temperature fluid and low temperature fluid in an alternating manner in a stacking direction of the units. The plates can be conformed to the thermoelectric module, and the stiffness of the plate can be increased.