PURPOSE: To provide a heat exchanging device in which dusts, etc., that attach to the contact sections between the heat exchanging device and the outside air are removed without requiring a long time and a large amount of labor.

CONSTITUTION: The inside of a casing 30 is divided by a partition plate 31 into the internal air side A and external air side B. The heat receiving section 45a of a heat pipe 45 is provided in the internal air side A and heat radiation section 45b of the heat pipe 45 in the external air side B, and the heat pipe 45 is tilted and it pierces through the partition plate 31 and is supported by it. An internal fan 47 is provided in the lower section of the heat receiving section 45a. An external fan 48 is provided in the upper section of the heat radiation section 45b of the heat pipe 45. Near the heat radiation section 45b of the heat pipe 45 an air blow-out device 49 is provided to remove dusts, etc., attached to the heat radiation section 45b by blowing out the air.