An apparatus and method is disclosed for the automatic treatment of workpieces with the aid of numerically controlled wire erosion machines. When an end point of a contour is reached during the treatment process, the drive and guide system for the wire-like or strip-like electrode is disconnected and beneath the workpiece the electrode is clamped by means of two feed rollers and provided with a groove by a grooving device. Then the upper drive device is switched on again and the electrode is broken off at the groove point. Following the positioning of the workpiece, the beginning of the electrode is threaded into the new starting bore of the contour by means of the two feed rollers, is gripped by a gripper following the workpiece, and is fed to the upper drive device.