The proposed guide shaft which is formed on a card holder has a support, lateral guides and a holding part. The latter is formed and arranged on the card holder in such a way that a tongue which points toward the entrance of the guide shaft and rests in a sprung fashion on the support or on a chip card which has been introduced is implemented, and a gap which corresponds only to the thickness of the chip card is produced between the card holder and the support in the vicinity of the contact field.