In this study the dynamic characteristics of a separator attached to two-for-one twister by bolt jointing were investigate by using finite element and experimental methods. Though in general, the bolt jointing has been considered as rigid joint, the boundary region of a separator was modeled by using the beam element with axial load in this paper. In order to assure the acceptability of the result of finite element, the experimental modal analysis was executed by the impact method. As a result of comparison between the finite element and experimental methods, assurance of a proposed finite element model with the beam element at the boundary region was obtained. The conventional separator needs to be improved in terms of cost and manufacturing process. The cost reduction and manufacturing process improvement are very important from an international competition point of view. Then, the new separator structure was prosed to enhance these factors without variation of dynamic characteristic. Through the finite element method and experimental modal analysis, it was found that the new model was well acceptable.