Device for clamping a medical guide wire, including a receiving body with a longitudinal opening traversing it for receiving the guide wire, which is displaceable and twistable in the longitudinal opening, and a clamping mechanism (5, 8; 5'), by the activation of which the displaceability and/or twistability of the guide wire received in the mentioned longitudinal opening can be blocked, characterized in that • the clamping mechanism (5, 8; 5') is formed either only at one end of the longitudinal opening of the receiving body or at each end of the longitudinal opening of the receiving body, • that the respective clamping mechanism (5, 8; 5') has - an expanded opening area extending transversely to the longitudinal opening of the receiving body at its associated end of the receiving body, which extends to the longitudinal opening over a segment, which is shorter than the longitudinal opening is long, - and a clamping member assembly (5, 8; 5') • and that the respective clamping member assembly (5, 8; 5') - is connected to the receiving body in elastically bendable manner between its expanded opening area and the mentioned longitudinal opening, - extends parallel to the longitudinal opening over a distance, which is shorter than the mentioned segment is long in the direction of the longitudinal opening, - and has an edge part (7, 7') facing the associated opening area on a side facing away from the concerned end and located in the opening area, on which the guide wire can be abutted blocking its displaceability and/or twistability after its swiveling from the longitudinal opening past the concerned end of the receiving body and the clamping member assembly (5, 8; 5') into the opening area present at this end of the receiving body. • the clamping mechanism (5, 8; 5') is formed either only at one end of the longitudinal opening of the receiving body or at each end of the longitudinal opening of the receiving body, • that the respective clamping mechanism (5, 8; 5') has - an expanded opening area extending transversely to the longitudinal opening of the receiving body at its associated end of the receiving body, which extends to the longitudinal opening over a segment, which is shorter than the longitudinal opening is long, - and a clamping member assembly (5, 8; 5') - an expanded opening area extending transversely to the longitudinal opening of the receiving body at its associated end of the receiving body, which extends to the longitudinal opening over a segment, which is shorter than the longitudinal opening is long, - and a clamping member assembly (5, 8; 5') • and that the respective clamping member assembly (5, 8; 5') - is connected to the receiving body in elastically bendable manner between its expanded opening area and the mentioned longitudinal opening, - extends parallel to the longitudinal opening over a distance, which is shorter than the mentioned segment is long in the direction of the longitudinal opening, - and has an edge part (7, 7') facing the associated opening area on a side facing away from the concerned end and located in the opening area, on which the guide wire can be abutted blocking its displaceability and/or twistability after its swiveling from the longitudinal opening past the concerned end of the receiving body and the clamping member assembly (5, 8; 5') into the opening area present at this end of the receiving body. - is connected to the receiving body in elastically bendable manner between its expanded opening area and the mentioned longitudinal opening, - extends parallel to the longitudinal opening over a distance, which is shorter than the mentioned segment is long in the direction of the longitudinal opening, - and has an edge part (7, 7') facing the associated opening area on a side facing away from the concerned end and located in the opening area, on which the guide wire can be abutted blocking its displaceability and/or twistability after its swiveling from the longitudinal opening past the concerned end of the receiving body and the clamping member assembly (5, 8; 5') into the opening area present at this end of the receiving body.