The search for alternative sources of energy from organic waste has been on in Nigeria. This report focuses on a simple design, fabrication and performance test of a prototype biogas digester. The volume of the digester was 340dm3 and that of the absorber/adsorber was 12.5dm3. The digester was fabricated using mild and stainless steels, styrofoam, polythene sheets and other materials. The digester can be moved about and agitated manually. In the performance test, 8.134L of biogas was generated within 14 days of anaerobic digestion of palm oil mill effluent (POME). The optimum pH and temperature for biogas production were 6.2 and 29oC respectively.