One of the main types of window regulators that are in current use is the X-arm type window regulator, which utilizes a linkage mechanism to raise and lower the window glass. One of the evaluation items that are necessary in analyzing the performance of a window regulator is the operating force that is required to operate the handle for moving up the window glass. It is difficult to estimate this force during the design stage. We have to take into consideration factors such as the influences of the various types of contacts and the elastic deformation of linkage arm. Therefore, we used the LS-DYNA, which is dynamic and kinematic nonlinear finite element analysis code, to develop a technique for analyzing the handle operating force. Then, we used this technique to conduct parameter studies to identify the factors that are believed to exert a greater influence on the operating force.