Parallel leaf springs are often used for precise linear motion because of their simplicity and freedom from static friction in cases where elasticity and high deformation are required. Using a parallel beam in force sensing requires minimum deflection and limited stress concentration. We previously proposed a unidirectional force sensor based on the H-slit parallel beam structure – an extension of conventional parallel beam. In this paper, we use finite element analysis (FEA) to investigate parallel beam structures that deflect easily in one direction, and evaluate the optimum profile for the notch in the H-slit beam and applications of the parallel beam structure.