Abstract. This paper focuses on sampled data control of an under-actuated electromechanical system with input delay, subjected to both parametric uncertainty and exogenous disturbances. The system is stabilized by a robust ஶ controller that stabilizes the closed loop system and attains a specified level of perturbation attenuation for all permissible parametric uncertainty. The proposed ஶ controller is designed for the orientation control of an underactuated electromechanical system which is a customized drill machine. The controller is designed on the basis of discrete time equivalent model of the system which is fully actuated and time invariant. The controller performance is evaluated on the basis of Monte Carlo simulations.