The production of extracellular thermostable amylase by Geobacillus was detected on nutrient agar plates containing 2.0% soluble starch at 65 oC. Bacterium was produced 8, 578 U/mL amylase under SmF. Thermostable amylase (size 42 kDa) showed optimum temperature 68 oC at pH optima 7.5. Geobacillus amylase was stable at 90 oC temperature and retained its 85% initial activity. The thermostable amylase was retained stability and activity in the presence of various denaturing agents such as SDS, Triton X-100, Tween-60, Tween-80. Ca+2, Cu+2 and Co+2 ions increased activity, while Na2EDTA, Hg+2, Zn+2, Sn+2 showed inhibitory effects. The thermostable amylase was stable, compatible and works at 10 mg/mL concentration of laundry detergents (Ariel, Ghari, Surf Excel, Wheel, Tide, Nirma, Rin and Henko). The Km and Vmax values were 2.702 mg/mL and 7692.3 mmol respectively.