To make a vent hole able to exhibit a ventilating functions and other function by devising the structure inside the vent hole.

The vent hole 10 is provided in such a manner as to pass through a partitioning member A as an outer wall of a building. A vent pipe 20 is internally inserted into the vent hole 10 in a double cylinder fashion to form a plurality of airways 11, 21 in the vent hole 10. At the pipe end on the outdoor side of the vent pipe 20, an exhaust fan 30 is provided using a solar battery 40 provided on the surface of a pipe end flange 22, as an operating power supply. On the other hand, in the vent hole 10, a splitter 50a is provided which is formed of a sectionally cross heat exchanging function material. By previously twisting the splitter 50a at a 90°, the passage of a light and sounds from the outside can be prevented and heat exchanging function can be exhibited during supplying/exhausting air.