A thermophilic $Alicyclobacillus$ $acidocaldarius$, which produces thermostable ${alpha}$-amylase, was isolated from the hot water effluent of a boiled rice mill near Tirupati, Andhra Pradesh, India. The effect of different culture conditions on the growth and production of extracellular ${alpha}$-amylase by thermophilic $A.$ $acidocaldarius$ was investigated in laboratory scale. The results showed that the optimum conditions for the production of ${alpha}$-amylase are a temperature of $60^{circ}C$, pH of 6.0, and medium starch concentration of 1.0%, and yeast extract and tryptone of 0.2%. Surfactants, like Tween-20 and SDS, up to 0.02%, were found to increase the bacterial growth and enzymes. Further increase in their concentration resulted in significantly decreased enzyme production.