Solar power desalination is one of the tools used in coastal areas that have a low electricity supply to get fresh water from seawater. One of the desalination devices that have been used in Indonesia, named solar still XX imported from another country. The geographical position of the two different countries affects the performance of the tool because it depends on the position yearly of the sun. This study aims to find the optimal inclination angle of solar still XX if used in Indonesia. The method is to find out the relationship between the angle of inclination to maximum temperature in a solar still XX condenser. By testing several inclination angles of 10, 15, 20, 25 and 30 degrees without watering, the maximum temperature of the condenser can be known for each angle of variation. The test location was carried out in the city of Depok (6°21'46.0"S 106°49'24.5"E), West Java in April 2018. Based on the test that has been done, the optimum inclination angle is 20 degrees with the maximum temperature in the condenser reaching 113.8 °C at 11.38 AM.