This paper poses the problem of designing Museum Appliances(MA), which are usable, i.e. easy to learn and easy to use. A recently proposed model of multimedia Human Computer Interaction is used to explore the dimensions of the MA usability, identifying the features which characterize this type of appliances, and to outline the an approach to usable MA implementation. The reasoning is bottom u, in that it starts form the study of some existing MA within the frame offered by the model, to derive the features which characterize an MA and the usability requests to be satisfied.