PURPOSE: To permit the air condition of a house under utilizing accumulated heat in a heat accumulating tank effectively by utilizing a heat pump type heating and cooling device in which an indoor machine is separated from an outdoor machine.

CONSTITUTION: The air-conditioning device is provided with an air type solar heat collector 2, a heat-accumulating tank 3 and the outdoor machine 5 of the heat pump type heating and cooling device 4, arranged in an air flow path 7, extending from the heat accumulating tank 3 and introducing air, which effects heat exchange between the accumulated heat of the heat-accumulating tank 3, into atmosphere. In case the heat accumulating temperature of the heat accumulating tank 3 is higher than the atmospheric temperature but is too low for heating the room R, underfloor air is discharged into atmosphere by opening dampers D5, D8 after being heated in the heat accumulating tank 3 while first heat exchanger 11 is heated by the outdoor machine 5 and warm-air is discharged into the room R by the indoor machine 6 to condition the air in the room. In case the room R is cooled at night or the like during room cooling season, only the dampers D5, D7 are opened whereby heat exchange between atmosphere, whose temperature is lower than the underfloor air, and the heat accumulating tank 3 is effected, thereafter, the atmosphere is discharged to the outside of the room through the air flow path 7. During this period, cool air may be delivered into the room from the indoor machine 6 after effecting heat exchange between the outdoor machine 5.