To enable a positive and fast stopping of function of a humidifier to be carried out in a heat exchanging and ventilation device having an automatic evaporating type humidifier storing water therein.

An air feeding passage in a heat exchanging and ventilation device of the present invention passes through a heat exchanger 4, a heater 5, a humidifying damper 7 for changing-over an air passage, a humidifier 3 and an air feeding fan 3 in this order. The humidifying damper 7 changes over a humidifying air passage passing through the humidifier 6 and a bypassing air passage bypassing this humidifier by making a selective closing of one communication port and the other communication port. In addition, air is heated by the heat exchanger 4 and then the air is heated by the heater 5 and after. With this arrangement as above, an air supplying amount is not lack even in the case of stopping of the humidifying operation. It is possible to extend a life of the humidifier 6. An efficient humidifying can be carried out.