Intervertebral disc prosthesis includes an upper plateau (16) with an outer surface (16a) bearing on an upper vertebra and with a surface (16b) directed towards the inside of the prosthesis, a lower plateau (18) with an outer surface (18a) bearing on a lower vertebra and with a surface (18b) directed towards the inside of the prosthesis, and a ball-type joint between the upper plateau and the lower plateau, having a bulged convex element (27), cooperating with a complementary recess of the bulged convex element (27) and coming into contact with the bulged convex element (27), the bulged convex element (27) including at least one slot (24, 25, 26, 28) that allows it to deform.