an automatic control system for operating the clutch of a car and capable of being attached to cars of manual shift transmission type comprising a servomotor mechanism forwardly and reversely rotated depending upon increase and decrease of supplied voltage to drive a clutch pedal in direction in which a clutch is connected and disconnected ; a circuit for converting the rotation number of engine to a pulse output to detect the rotation number of engine ; a frequency - voltage converter circuit for supplying to a servomotor an output voltage responsive to said pulse output ; and a switching means connected on the way of a voltage supply line extending from the frequency - voltage converter circuit to the servomotor mechanism and changing voltage supplied to the servomotor mechanism by manual or foot operation to forwardly and reversely rotate the servomotor mechanism .