In this study, an optimized Air-Curtain Device(ACD) was developed by Computational Fluid Dynamics(CFD). Case studies were performed with two variables: a discharged velocity and an angle. The factors that affect the air curtain formation are the discharged velocity and temperature. The CFD was used to determine the optimum deflection modulus of the ACD, and the analysis was verified by comparing it with the experimental results. In the case of an open type smoking booth using an air curtain, the Reynolds number and the discharge angle of the air are very significant factors. The optimized efficiency of the ACD is shown at the Reynolds number of 6542 and the degree of 30.