To miniaturize and reduce running costs of a heat exchange ventilation system 10 by improving heat exchange efficiency between supply air and exhaust air in the heat exchange ventilation system.

The heat exchange ventilation system 10 is provided with the passage 38 for heat exchange ventilation connected to a heat exchange ventilation device. The passage 38 for heat exchange is a two-way pipe partitioned by a partition 44 having thermal conductivity. The partition 44 is a flat plate shape in pipe ends, and it is machined into a waveform for increasing a surface area in other portions. Heat exchange of the supply air introduced from outdoors, and the exhaust air exhausted from indoors is carried out via the partition 44 in the passage 38 for heat exchange ventilation, and heat exchange is carried out in the heat exchange ventilation device also.