We investigate the melting transition of the solids interacting through a simple pairwise potential using conventional and Wang-Landau Monte Carlo simulation. In the simulations, the atomic displacement is discretized for describing the atomic vibration and each atom is confined within its Voronoi polyhedron. The melting point can be uniquely determined by Wang-Landau approach while the temperature hysteresis inevitably appears in the conventional method. The obtained results show typical feature of first-order transition which is the discontinuous change in the internal energy. We discuss the relation between the limit of superheated state and intrinsic instability of the system through the comparison with two results.