A test device for an ossicular prosthesis for implantation in the middle ear that includes a first fastening element, a second fastening element and a connecting element that connects the two fastening elements in a sound-conducting manner. Parts of the ossicular prosthesis are made of a material having memory effect and subjected to shape-altering thermal treatment at implantation. The test device also includes a device for determining an optimized power setting or an energy application site for preparing parts of the ossicular prosthesis to be subjected intraoperatively to thermal treatment using a prosthesis mock-up that is identical in design to the ossicular prosthesis in terms of material, geometric shape, and manufacturing method in the parts to be subjected intraoperatively to thermal treatment.