To provide a rooftop-installed hood box, simplifying mounting work for a hood box mounted on the wall surface of a dovehouse to allow a worker to safely and easily perform the work by himself.

The rooftop installed hood box mounted on the wall surface P1 of the dovehouse P includes: a mounting frame 10, side plates 2, a base plate 30, an upper lid 40 and a front lid 50. The mounting frame 10 fixed to the wall surface P1 of the dovehouse P is provided with a plurality of threaded holes 11 bored for screwing the end parts of right and left side plates 20 to the mounting frame 10 fixed to the wall surface P1 of the dovehouse P. One of the threaded holes 11 is provided in a cutout shape to form a cutout threaded hole 12. A connecting bolt 1 is previously mounted in a threaded hole 21 of the end part of the side plate 20 located to be screwed in the cutout threaded hole 12. The connecting bolt 1 is slid and inserted in the cutout threaded hole 12 from the side to temporarily stop the side plate 20.