To provide an external wall panel dispensing with a large opening section equipped with a ventilating hood.

The external wall panel 8 is so constituted that inside opening sections 9 are provided to the inside of the upper end section, outside opening sections 10 are provided to the outside of the lower end section and that it has air supply outlets 12 bent in the shape of a crank connecting the opening sections 9 and 10 with air passages 11. As an external wall material of a panel 8 structure of a building in a refuse incineration plant, is used to take in the open air through the outside opening sections 10 of the external wall panel 8, the air passages 11 and the inside opening section 9.