Abstract: For patients who suffer from a middle ear disease interrupting or destroying the ossicular chain but whose inner ear is intact yet, the invention provides a prosthesis (10) which includes in a casing a complete acoustical transmission system (12, 26, 50) and is adapted to be dismantled following a performance check, then to be mounted stepwise and to be entirely implanted. At the same time, the inflamed middle ear cavity is completely wiped out. Adjacent an inner coupling unit (12) to the oval window (V), there is cover unit (22) or a conduit (24) at the round window (F) of the inner ear. A transfer unit (26) having an artificial tympanic membrane (28) comprises an acoustically transmissive connection (42) to a mastoid unit (50) having a damping insert (54). The outer wall portions (28, 52) of the prosthesis (10) are epithelialized.