To provide a box-shaped ventilation member capable of undergoing a fine adjustment in order to achieve a desired height without forming a folding line, being inexpensively supplied on the strength of a simple composition, and being used for a lean-to part.

In the ventilation member, there is installed a square cylinder- shaped box member 2 whose upper and lower surfaces are opened, the lower edge of the side surface on the longer side of the member 2 is extended and folded so as to form a stationary plate 4, and a vertically elongated separating line 3 is sometimes formed in the side surface on the shorter side of the member 2.