An insertion device for an infusion set, the device including a retention means by which the infusion set can be temporarily held on the device and drive means including a pretensionable spring for providing drive energy for an insertion movement of the infusion set, wherein the infusion set is secured by the retention means by clamping when the retention means is in an engage position and can then be moved, with simultaneous pretensioning of the spring, to an insertion movement starting position, wherein the infusion set is already separated from the retention means at the start of the insertion movement, and wherein the infusion set moves through at least part of the insertion movement free of the retention means.