The present invention relates to a ventilating apparatus for ventilating a display of a hall door with clean air, and the ventilating apparatus includes: a rectangular parallelepiped monitor box MB which is fixed onto a rear surface of a hall door D at a rear side of an opening 15 of the elevator hall door D made of metal, and protrudes at the rear side of the elevator hall door D to accommodate a monitor M; a monitor M which is fixed into the monitor box MB; a tempered glass plate 20 which is disposed at the rear side of the opening 15 of the elevator hall door D, and sized to cover the entire monitor to protect the monitor M from frontal impact; a plurality of inlets and outlets 52 and 54 which is formed at a central lateral portion D1 of the hall door D and connected to the interior of the monitor box MB; and two blower fans F1 and F2 which are installed in the monitor box MB between the monitor M and the inlets and outlets 52 and 54, and provide air, in which when the blower fans F1 and F2 operate, air in a building hallway or an elevator cage flows into the monitor box MB through the inlets 52 among the inlets and outlets 52 and 54, cools the monitor M, and then is discharged to the building hallway or the cage through the outlets 54 among the inlets and outlets 52 and 54.