The ball and beam system is one of the most popular models for studying control systems because of its nonlinearity and several control techniques have been proposed. Sliding mode control is a popular robust control method which rejects the external disturbance. In this paper, we propose a robust controller using the ${epsilon}$-sliding surface. On the ${epsilon}$-sliding surface, the system robustness and convergence can be manipulated via a use of ${epsilon}$. We show the stability analysis and convergence analysis on the ${epsilon}$-sliding surface. In addition, the experimental results show the validity of the proposed controller.