To provide a respiratory organ type ventilation system in which a ventilation unit changes over aspiration and evacuation for prescribed time to generate an air flow.

This invention relates to a respiratory organ type ventilation system comprising a ventilation unit having at least a fan and a heat storage element so as to ventilate between indoor intake air and surrounding atmosphere and a controller unit for controlling an operation of the ventilation unit. The ventilation unit changes over the aspiration and evacuation for prescribed time so as to generate an air flow just like an animal's aspiration activity, resulting in that air in an object area is entirely flowed well or ventilation can be carried out without any stagnation and its installation work can be simplified.