PURPOSE: For improving detection sensitivity, to detect dew directly with a dew detector provided in the high-temperature, high humidity air passage preceding a heat exchanger.

CONSTITUTION: This clothes drier having a rotary drum 2 rotatably provided in the body 1 thereof is supplied with the air heated by the heater 3 fitted in a circulation air passage by the operation of an air circulating fan 5. The heat exchanger 6 placed in the inner bottom section of said body 1 removes moisture by cooling the high-temperature, high humidity air (a) passing through a pipe 6' with the atmosphere (b) fed by another blower. A dew detector 8 is installed in the high- temperature, high-humidity air passage 9 preceding said heat exchanger 6. Said detector 8 works to lower resistance value when the dew having attached thereto has vanished, i.e. clothes have dried. This is utilized for stopping operation by the closure of a switch 15 by a control circuit 16.