This article describes the fixed bed biomass gasifier operation designed and built by the Clean Development Mechanisms and Energy Management research group, the gasifier equipment and the measurement system. The experiment involved agro-industrial residues (biomass such wood chips, coconut shell, cocoa and coffee husk); some temperatures along the bed, its pressure, inlet air flow and the percentage of carbon monoxide and carbon dioxide in the syngas composition were measured. The test results showed that a fuel gas was being obtained which was suitable for use with an internal combustion engine for generating electricity because more carbon monoxide than carbon dioxide was being obtained during several parts of the operation. The gasification experimentation revealed that a gasifier having these characteristics should be ideal for bringing energy to areas where it is hard to obtain it (such as many rural sites in Latin-America) or other places where large amounts of agro-industrial wastes are produced. Temperatures of around 1,000°C were obtained in the combustion zone, generating a syngas having more than 20% carbon monoxide in its composition, thereby leading to obtaining combustible gas.