Finite Elements Method (FEM) and Finite Difference Method (FDM) in the Euler implicit approach, were used in order to determine the bi-dimensional electromagnetic field. of an oscillating punctual source inside a square geometry with three reflective boundaries and an absorbing one. Although the main approach consist in solving the wave equation for the electric field., it was decided to use the approach of electromagnetic potentials V and A because those potentials give a simpler solution for both, the electric and magnetic field. Besides, a comparison with theory was made, solving for an electromagnetic field without boundaries produced by an oscillating punctual source.