The invention relates to an inlay which is suitable for an endoprosthesis, in particular a joint prosthesis. This inlay essentially comprises a flexible pad 5, a first flexible membrane 2 resting on the pad, and a second membrane 3, extending parallel to and above said membrane, in which support elements 5 are clipped. The support elements 4 rest with their undersides 4e on the first membrane 2, and with their surfaces 4a form a sliding and bearing surface for the joint head which is to be connected to the bone. The pad 5, composed of a liquid or gel-like medium, is situated in a well 1, and the two membranes 2 and 3 are fixed to the lateral walls 1a of the well by means of screws 6 and nuts 7.