Capillary connection unit for analysis devices and medical devices - comprising a capillary having at least one end section and a free end thereon, - comprising at least one connection element arranged on the end section of the capillary, wherein the connection element has an axial guide-through through which the capillary runs, - comprising a sealing element surrounding the capillary at least in the region of its free end, and - comprising a metal sleeve element which radially externally surrounds the sealing element at least in regions and which has a first end (14.1) facing the connection element and a receiving region (14.3) facing away from the connection element, wherein the connection element with the free end of the capillary is configured to be detachably connected to a counter element and to exert an axial thrust force onto the sealing element, characterized in that the sleeve element is axially movably guided in relation to both the connection element and the capillary with the sealing element, that an inner diameter d iH of the sleeve element in the receiving region (14.3) facing away from the connection element is at least as large as the outer diameter d aD of the sealing element, the sleeve element being configured to substantially completely accommodate the sealing element in its receiving region (14.3), and that the sleeve element has at its first end (14.1) facing the connection element a first thrust surface (15.1) facing the connection element in the axial direction for receiving the thrust force of the connection element and only one radially internal second thrust surface (15.2) facing the sealing element and axially spaced from a second end (14.2) facing away from the connection element for forwarding the thrust force to the sealing element, and in that a stationary securing element is arranged radially externally on the capillary in a region directly adjacent to the sealing element towards the connection element and is connected to the capillary in a firmly bonded manner and is connected to the sealing element in a firmly bonded and form-fitting manner via a toothed feature. - comprising a capillary having at least one end section and a free end thereon, - comprising at least one connection element arranged on the end section of the capillary, wherein the connection element has an axial guide-through through which the capillary runs, - comprising a sealing element surrounding the capillary at least in the region of its free end, and - comprising a metal sleeve element which radially externally surrounds the sealing element at least in regions and which has a first end (14.1) facing the connection element and a receiving region (14.3) facing away from the connection element, wherein the connection element with the free end of the capillary is configured to be detachably connected to a counter element and to exert an axial thrust force onto the sealing element, - comprising a sealing element surrounding the capillary at least in the region of its free end, and - comprising a metal sleeve element which radially externally surrounds the sealing element at least in regions and which has a first end (14.1) facing the connection element and a receiving region (14.3) facing away from the connection element, wherein the connection element with the free end of the capillary is configured to be detachably connected to a counter element and to exert an axial thrust force onto the sealing element, characterized in that the sleeve element is axially movably guided in relation to both the connection element and the capillary with the sealing element, that an inner diameter d iH of the sleeve element in the receiving region (14.3) facing away from the connection element is at least as large as the outer diameter d aD of the sealing element, the sleeve element being configured to substantially completely accommodate the sealing element in its receiving region (14.3), and that the sleeve element has at its first end (14.1) facing the connection element a first thrust surface (15.1) facing the connection element in the axial direction for receiving the thrust force of the connection element and only one radially internal second thrust surface (15.2) facing the sealing element and axially spaced from a second end (14.2) facing away from the connection element for forwarding the thrust force to the sealing element, and in that a stationary securing element is arranged radially externally on the capillary in a region directly adjacent to the sealing element towards the connection element and is connected to the capillary in a firmly bonded manner and is connected to the sealing element in a firmly bonded and form-fitting manner via a toothed feature.