An intervertebral implant having a lower implant part and an upper implant part. The lower implant part has an outer casing, a hollow cylindrical cavity, an axis of rotation, and an apposition part for contacting the lower vertebra. The upper implant part has an essentially circularly cylindrical shaft, which has an external thread, for extending into the cavity of the lower implant part, an axis of rotation, and an apposition part for contacting the upper vertebra. The two implant parts may be secured to prevent rotation about their axis of rotation. The implant also includes a ring with an internal thread, disposed between the two implant parts and interacts with the external thread of the upper implant part. Rotating the ring permits the distance between the two apposition parts to be adjusted. The ring may be axially fixed but rotatively movably with the lower implant part.