The electromagnetic forming process (EMF) is one of the high speed forming processes using the Lorentz force. In this study, numerical simulations were conducted, to set up an EMF process with a middle rectangular block. A 3D electromagnetic numerical model was considered, based on a spiral forming coil. In the numerical simulation, an RLC circuit coupled with the spiral coil was made to consider the design parameters, such as system input current and electromagnetic force. Magnetic fields and current density were described, to consider their values and direction with time passing. Furthermore, plastic deformation behavior was considered at each time step. A 32 kJ EMF machine was set based on the numerical simulation results, to conduct the test. The experiment was performed in 20 kJ, to deform Al 3104 with a thickness of 1.0 mm. The test workpiece was well formed to fit with the die of the forming set. In order to verify the simulation result, the Z-displacement of the final shape was measured by 3D scan, and compared with the Z-displacement of the simulation result. The measured experimental profiles and numerical final shape are in good agreement, when accounting for the sheet deformation.