PURPOSE: To increase the ventilation efficiency in a garret, by providing an outside air inlet member at the part constituted of a fascia board and a flashing plate at eaves, provided at the eaves side thereof and provided with a folded- back part at the lower end.

CONSTITUTION: An outside air inlet member 3 is constituted of an insert 5, an air suction part 8 bent at an almost right angle against the insert 5 and provided with a ventilation hole 9, and a fitting part 6 bent at an almost right angle against the air suction part 8. A folded-back part 4 where the lower end thereof is bent to the fascia board 1 side is fitted to the flashing plate 2 at the eaves. The insert 5 of the outside air inlet member 3 is inserted in the folded-back part 4 of the flashing plate 2 at the eaves and the fitting part 6 of the outside air inlet member 3 is fixed at the fascia boars 1 with nails 7. Accordingly, the flow path from the outside air inlet part to an air path 16 is of an extremely simple structure. In this way, the ventilation efficiency in the garret is increased.