Abstract: A door drive apparatus with a locking mechanism for elevator doors permits the opening of the car door situated in the region of a floor together with a coupled-on shaft door, driven automatically in the normal case or manually in the case of a power failure. If the elevator car is situated outside a floor region, the car door remains locked. A control cam mounted at the upper end of a car door leaf is connected with a door drive by a belted drive means and causes a low-jerk opening and closing of the car door at the closing end of travel. The control cam is connected by a pull rod to an entraining member parallelogram for the coupling of the shaft door to the car door. A locking mechanism on the upper end of the same door leaf has an actuating roller which is actuated by a double lever connected to the control cam and the pull rod for the unlocking when the car is located in the door opening region of a floor.