It has been known that the uniform stress surface implies the least strain energy and surface area. The problem, which studies minimal surfaces spanned in boundaries, is called the Plateau problem. The problem is generally a multimodal nonlinear problem with some extremums. The sequential computation to minimize the surface area yields the coordinates of surfaces to the prescribed reducing area. This process leads to an optimization to minimize the surface area. Searching for any initial surfaces, the obtained minimal surface may be a local optimal solution and not always a global optimal solution. A numerical strategy is necessary to avoid capturing local minimal solutions and to obtain the least area surface. The tunnel method has been utilized for the global optimization in multimodal problems. This chapter presents the algorithm to find minimal area surfaces using the tunnel method.