To secure high dehumidifying efficiency by bringing circulation air into contact with cooling water of a large free surface area for a long period so as to execute heat exchange.

This system is provided with a clothes drying drum 5 arranged within a drier main body 1, a circulating air duct 13 whose one side is communicated with the drum entrance 11 of the drum 5 and whose the other side is communicated with the drum exit 15 of the drum 5 to circulate circulating air by a blowing fan 19 and a drying heater 17 heating circulating air within the air duct 13, and the fan 19 is arranged between the exit 15 and the heater 17. On the other hand, at the casing part 21 of the fan 19, cooling water is made to flow along a casing inner wall surface 31 to bring the circulating air into contact with the cooling water to cool and dehumidify the circulating air.