To provide a corresponding to heating type desiccant air-conditioning device for conducting heat recovery, even during heating and can also serve as a humidifier during heating and cooling, and is very simple in constitution.

The desiccant air-conditioning device 2 comprises a counterflow type flow passage, consisting of two flow passages 22 and 23; a sensible heat exchanger 6; a dehumidifier 4; a heater 16; a first flow-switching means 26 connected to the air introduction sides of the two flow passages 22 and 23 and alternately switching the two flow passages 22 and 23 to an outdoor or an indoor spot; and a second flow-switching means for alternately switching the two flow passages 22 and 23 to an outdoor or an indoor spot for communication. A humidifier 18 for conducting humidity conditioning of air supplied in a room is installed on a flow passage 32 to intercouple a second flow-switching means 27 and an indoor spot.