The application provides a unipolar cannula that can have a metal cannula tube, a body part made of an electrically insulating plastic, attached to the proximal end of the cannula tube, a connector disposed on the body part for the introduction of a liquid into the cannula tube, and a stimulation cable, an electroconductive wire of which electrically contacts the cannula tube in the region of the body part. The stimulation cable can be mounted laterally on the body part by a mounting part made of an electrically insulating plastic, where the mounting part has an electroconductive contact element which is connected conductively to the wire, and where the contact element engages into a recess of the body part and contacts the cannula tube when the mounting part is mounted on the body part.