In many developing countries wood is the main energy source, and its exploitation is accelerating deforestation and desertification. In order to reduce wood consumption, an innovative biomass press was designed, aimed at providing alternative fuel by compacting dry waste biomass. The machine is based only on mechanisms, and can work by animal power, in order that it can be used in places where there is not electric power. The main machine element is a cam, designed according to the criterion of making manual running possible, on the basis of an experimental biomass behaviour law. The whole machine design was conceived with the aim of allowing construction in the developing countries. A prototype for research was realised, equipped with an electric motor and electronic control system. Biomass compaction tests were carried out, from which the machine characteristics were derived, and the validity of the biomass behaviour model was confirmed. Pilot plants, both manual and electric, were realised in Burundi and Chad, obtaining encouraging results as far as the appropriateness of this technology to developing countries is concerned.