A power generation device comprising: a frame including a through hole to pass therethrough in a first direction and form an inner surface; a duct disposed in the through hole of the frame and having a flow path such that a first fluid flows in a second direction perpendicular to the first direction; a first thermoelectric module including a first thermoelectric device disposed on a first surface of the duct and a first heat dissipation fin disposed on the first thermoelectric device; a second thermoelectric module including a second thermoelectric device disposed on a second surface opposite to the first surface of the duct and a second heat dissipation fin disposed on the second thermoelectric device; characterized in that a plurality of tilting members (2000, 2100) is disposed in the inner surface of the through hole along the second direction on the duct and faced to each other; and a guide member disposed on a third surface disposed between the first surface and the second surface of the duct, wherein the first surface and the second surface face each other along a third direction perpendicular to the first direction and the second direction, wherein a second fluid passes through the through hole along the first direction, wherein the guide member extends along the second direction between the plurality of tilting members (2000, 2100), wherein each of the plurality of tilting members (2000, 2100) and the guide member includes a tilting surface, wherein a tilting direction of the tilting surface of the guide member is different from a tilting direction of each tilting surface of the plurality of tilting members (2000, 2100), wherein the tilting surface of the guide member is tilted so that the second fluid branches and flows along the first direction, wherein a separation distance between the tilting surfaces of the plurality of tilting members (2000, 2100) is greater than or equal to a length of the guide member along the second direction. a frame including a through hole to pass therethrough in a first direction and form an inner surface; a duct disposed in the through hole of the frame and having a flow path such that a first fluid flows in a second direction perpendicular to the first direction; a first thermoelectric module including a first thermoelectric device disposed on a first surface of the duct and a first heat dissipation fin disposed on the first thermoelectric device; a second thermoelectric module including a second thermoelectric device disposed on a second surface opposite to the first surface of the duct and a second heat dissipation fin disposed on the second thermoelectric device; characterized in that a plurality of tilting members (2000, 2100) is disposed in the inner surface of the through hole along the second direction on the duct and faced to each other; and a guide member disposed on a third surface disposed between the first surface and the second surface of the duct, wherein the first surface and the second surface face each other along a third direction perpendicular to the first direction and the second direction, wherein a second fluid passes through the through hole along the first direction, wherein the guide member extends along the second direction between the plurality of tilting members (2000, 2100), wherein each of the plurality of tilting members (2000, 2100) and the guide member includes a tilting surface, wherein a tilting direction of the tilting surface of the guide member is different from a tilting direction of each tilting surface of the plurality of tilting members (2000, 2100), wherein the tilting surface of the guide member is tilted so that the second fluid branches and flows along the first direction, wherein a separation distance between the tilting surfaces of the plurality of tilting members (2000, 2100) is greater than or equal to a length of the guide member along the second direction.