PURPOSE: To improve cooling efficiency for an electric part and to prevent penetration of water to the interior by providing a blowoff guide part to guide heat exchange air, by means of which an electric part in an electric part box is cooled, from the one end of a heat sink to gaps between adjoining radiation fins, and a discharge guide part to guide heat exchange air to the low pressure side of an outdoor blower.

CONSTITUTION: A blowoff guide part 39 is composed by a space between the one end of a heat sink 38 and inner surface of an electric part box 3, and a discharge guide part 40 is formed in a portion positioned facing the fan low pressure side of an outdoor blower 33. Heat exchange air guided from the blowoff guide part 39 between radiation fins 38b of the heat sink 38 is discharged and guided from a discharge guide part 40 to the outside of the electric part box 34 and further guided to the lower pressure side of the outdoor blower 33. Therefore, heat exchange air guided in the electric part box cools electric parts 37a and 37b and is smoothly discharged to the outside, and cooling efficiency can be improved. Further, even when water drops are flied by a fan 33a of the outdoor blower 33, the water drops can be prevented from entrance to the box through the shape of the radiation fin 38b and the electric part box 34.