To provide a fire preventive and fire resisting structure of an eave- soffit part and the like, which can prevent hot air from intruding into an under surface of eaves even if a louver part, formed with a vent hole, of a fire damper undergoes deformation, etc., due to heat at a fire.

An eave-soffit plate 3 is formed with an opening 3a for ventilation in the under surface of the eaves, and the fire damper 6 is fitted into the opening 3a. The fire damper 6 makes a closing cover driving part 6c operate at the fire so as to make the vent hole 6b closed with a closing cover 6e. A thermally expansive fire-resisting material 6e is provided in a surface on a closing side of the closing cover 6e of the fire damper 6. The material 6e is expanded (foamed) due to the heat at the fire so as to cover the vent hole 6b. Consequently, the hot air can be prevented from intruding into the under surface of the eaves even if a place (the louver part), at which the vent hole 6b is formed, undergoes the heat deformation, etc.