An electric element (Peltier element composite) is disposed in a boundary between an outside air introduction passage and an inside air introduction air passage (114). The Peltier element composite absorbs heat from the inside air in the inside air introduction passage to cool and dehumidify the inside air and radiates heat to outside air in the outside air introduction passage. The inside air and outside air are blown out from a defroster air outlet through a second air passage. In this way, it is possible to increase an amount of introduced inside air and to improve the heating performance while maintaining the defrosting performance.