Mathematical models of the plant, in general, are not accurate. The errors in model give rise to model uncertainty. The robust design techniques take care of this. Hinfin- theory facilitates design of controller using Hinfin- norm which provides robustness properties. Then a cost function or performance index is selected that represents the quality of the system performance. After a controller structure, a cost function and some constraints have been specified, the problem is posed as nonlinear optimization problem which is solved using the simulated annealing algorithm due to Corona et. al. M-files using MATLAB programming are written for the design and analysis for the design example.