Abstract: The present invention concerns an artificial joint, in particular an endoprosthesis to replace natural joints, consisting of at least two artificial joint parts with curved articulation surfaces, wherein, on each of the articulation surfaces, a contact line (k) in the shape of the arc of a circle is formed, which is a section of a contact circle with a center (M), lying in a plane. The articulation surfaces are arranged as a pair with respect to one another in such a manner that the contact lines (k) can roll onto one another, and vertical to the plane of the contact circles, are intersected at an intersection point (S) by axes (m) passing through their center (M).