An ossicle prosthesis (10) includes a first securing element (11) and a second securing element (12), the second securing element connected to a member of the ossicle chain. The ossicle chain ends at the first securing element in a ball joint, which includes two struts (13, 13') solidly connected to the first securing element (11). The two struts enclose a gaplike space, in which a ball (14) is pivotably supported in two recesses (15), the ball (14) being part of an elongated shaft (16) that connects the first and second securing elements and includes many balls (14, 14', 14'') adjacent to one another. The elongated shaft is displaceable through the gaplike space between the two struts and through a perforation (17) in the first securing element, where one of the balls snaps between the respective recesses. The gaplike space can be made narrower between the two struts (13, 13') of the ball joint for fixation of the shaft (16) after the desired length has been adjusted.