To provide a throating having a ventiduct capable of guiding moisture to a venting space, etc. and a ventilation structure of a building external wall making use thereof.

The throating 11 is equipped with an upper plate section 11a mounting one surface side of a plate surface to an indoor side wall member 5 in the venting space 7 of the building external wall 1 and plate sections (an inclined plate section 11b and a lower plate section 11c) consecutively provided to the lower end of the upper plate section 11a for a water drip. The upper plate section 11a has the ventiduct (a moisture transmission hole 12 and the ventiduct) ventilable to the other surface side of the plate surface from the one surface side of the plate surface. In the vent structure of the building external wall, the venting space 7 communicating the lower end with the atmosphere through a lower vent 6 of the outdoor side wall member 4 is formed between the indoor side wall member 5 of the building external wall 1 and the outdoor side wall member 4 on the outside so that moisture permeating into the venting space 7 from an indoor space (habitable room 2) of a building through the indoor side wall member 5 can be guided to the atmosphere through the vent 6. The throating 11 is placed in the lower end section of the venting space 7 by bringing into contact with the indoor side member 5.