The stability of enzymes to heat and pH is one of the most important determining factors in their application. In this research, achieving thermostable and pH-stable cellulase was aimed by screening in one of the Hot springs of Garab in northeast Iran. The samples collected from one of the Hot springs of Garab, in Razavi Khorasan province in Iran, were used to isolate, screen, and identify bacteria capable of producing thermostable cellulase. The cultures were cultured at 45°C and under aerobic conditions. The bacteria were isolated on a CMC agar medium. Initial screening of the isolates was done based on specific culture medium, salt tolerance, and temperature changes. Then, their additional screening was done by evaluating endoglucanase activity at different temperatures and pH using qualitative and quantitative methods. Finally, the molecular identification of the selected isolate was done by 16S rRNA gene sequencing. The results of this study, led to the introduction of a selected strain identified primarily as Bacillus sp. G362, a moderate halophile growing in 6%(w/v) salt concentration. It showed high endoglucanase stability at 55°C and high stability in a wide range of acidic and alkaline pH. The studied Hot spring, like some other Iranian Hot springs, has cellulase-producing bacteria, which Bacillus sp. G362 is capable of producing endoglucanase showing the thermostablity and pH stability at a wide range of alkaline and Acidic pH. In addition, the specific endoglucanase gene of G362 Bacillus sp. can be identified through molecular methods and used for further research including structural studies. It may even be used as a protein template in protein engineering.