Abstract: Single slope solar still absorbs the thermal energy from sunlight to distillate polluted water into clean water in an enclosed space. Principal of heat transfer and energy balance were the governing equations for the operation of single slope solar still. A mathematical model was developed to express these thermodynamics behaviours. In the model, critical parameters had been identified, such as slope angle of glass cover, mass of water in basin and wind speed. Simulation had been carried out and results revealed the importance of the slope angle matching the latitude of the experimental location, the increasing of water mass in the basin leading to decreasing of clean water production and the presence of wind speed also increase the output only when the sunlight is still sufficient.