The invention relates to a puncture instrument for inserting elongated medical accessories in the body. The puncture instrument comprises a puncturing aid having a metallic shaft (1), its distal end terminating in a cannula tip (2) and its proximal end in a cannula holder (3), a handling means (4； 34) for advancing the puncturing aid, and an axially movable elongated medical accessory (11) inserted in the puncture instrument, the components making said instrument up being already assembled. The distal end (12a or 12b) of the accessory is placed at a predetermined position in the puncture instrument, the handling means is shaped as a handle element having a surface design which can be easily gripped by the fingers and is connected to the cannula hub (5), the accessory inserted in a channel formed by the shaft and the handling means has a greater length than the surrounding channel, the medical accessory (11) can be moved relative to the surrounding shaft (1) and the handling means (4； 34) projects proximally from the handling region.
