This study aims to apply some conservation techniques on an archaeological pottery sarcophagus dating back to the late period in Egypt. It is from the expedition of the Faculty of Archaeology, Cairo University, Egypt (at Saqqara, season 2016/2017). The condition of the sarcophagus was weak and it suffered from many deterioration aspects including the accumulation of dirt and soil remains, cracks, decay, fragility of pottery body and crystallization of salts. Furthermore, many sherds were broken and some were missing. It should be mentioned here that the analysis and investigations for this sarcophagus were done in a previous study. Prior to conservation, documentation was performed using AutoCAD to demonstrate the deterioration aspects and prepare a damage map for the archaeological sarcophagus. Conservation techniques included both mechanical and chemical methods, including soft brushes and diluted acetone with distilled water. The joining process for the sarcophagus sherds was performed using paraloid B-72 60% dissolved in acetone. Finally, the completion process was applied with a mixture of dental plaster with grog and primal AC33. The results of the conservation techniques proved that cleaning revealed the aesthetic value of the object, while the joining and completion of missed parts increased the strength of the object studied.