The main goal of this study is to improve the performance of a pyramid-shaped solar still by studying some effective parameters on the still distillate yield and still instantaneous efficiency including solar radiation intensity, brine depth, water salinity, temperature difference between the glass cover and the brine. Thus a simple basin pyramid- shaped solar still with total area of 0. 64 m2 covered with four triangle clear sheets of glass with 3 mm in thickness without frame was fabricated and tested with auxiliary black materials in basin from 8 am to 6 pm under Zagazig city local climatic conditions (Latitude 30.5° N). The solar still performance was evaluated under three levels of brine depth (4 ,8 and 10 cm),two levels of water salinity (15000 and 35000 ppm) intended to simulate brackish water and seawater respectively using auxiliary black materials including black sponge cubes and black stones. The results showed that around the noon hour, using the black sponge cubes at water depth of 4 cm and water salinity of 15000 ppm gave the highest still instantaneous efficiency of 46.15 %, the highest temperature difference between the glass cover and the brine of 32.40 °C, the highest distillate and accumulated yield of 630.40 ml/h and 3620.45 ml respectively. Hence, it is recommended to operate the solar still at brine depth of 4 cm and water salinity of 15000 ppm using black sponge cubes to obtain the highest values of the distillate yield, accumulated yield and the instantaneous efficiency.