A method for controlling a specific resistance of a single crystal in a Czochralski-method type single crystal pulling apparatus having a hermetical chamber in which the single crystal is pulled up from a polycrystal melt and an inert gas supply and exhaust system by means of which an inert gas is supplied to the hermetical chamber and exhausted therefrom; the method being characterized in that the pneumatic pressure in the hermetical chamber and the supply rate of the inert gas are controlled in accordance with a prepared control pattern with respect to the passage of pulling time.