In spite of the importance of the finite element method analysis in the mechanical design, there are a few research works in the prosthetic hands design area that use this tool. This work uses the finite element method to perform a structural analysis of a prosthetic hand prototype during the cylindrical and tip grasp. Through geometric relations, a set of equations was developed in order to define the position of the prosthesis elements from the position of the actuator. The loads in the numerical analysis were calculated by modeling a static analysis, in which the forces that the fingers of the prosthesis can exert at the tip were obtained. The results are presented in a graphic form showing the load of the fingertip as function of the position of the actuator and the maximum force that can be exerted. It is shown as well the field stress present in the mechanism of the hand simulator for the most critical position and the field stress of the prosthesis prototype. Both parameters were calculated with the use of ANSYS Workbench 2.0 ®