The invention relates to a ceramic insert (1) for sliding pairs in endoprosthetics. Said insert (1) has an outer face and an inner face; on the inner face, a hemispherical sliding area (2) is formed for accommodating a spherical sliding partner. In order to be able to reduce the thickness of the metal shell plus the insert such that the pelvic bone does not have to be milled as deep down, according to the invention, the insert (1) is designed as a ring or in an annular form.