Abstract: This fire barrier ventilation device has a duct (15) surrounded by a sheath (28) made of fire barrier protective material. A fire barrier ventilation sealing assembly (22), formed by a frame having grilles (2, 3) fixed to refractory material plates (4, 5) each bearing a plate (10, 11) of intumescent material, is fixed to the duct facing a ventilation orifice or slit (20) in the latter. A ventilation passage (12) located facing the ventilation slit (20) of the duct (1) containing cables (C) to be protected is formed between the plates (10, 11) of intumescent material.