Abstract: A control method for controlling an idle rotation speed of a fan clutch may include sensing an idle state of a cooling fan by comparing a coolant temperature with a predetermined operating temperature, inputting a rotation speed of the cooling fan and the coolant temperature to an engine control unit (ECU), outputting a valve control signal controlled by the coolant temperature and the rotation speed of the cooling fan in the ECU, inputting the valve control signal to a valve, and opening/closing the valve according to the valve control signal. An apparatus for applying the method may include the fan clutch which comprises a housing, a rotor, a cover, an oil chamber, a valve, an antirotation bracket connected to the fan clutch and transmitting data, and an ECU calculating the valve control signal.