We used the enalapril maleate to identify the degradation products by mass spectrometry using the technique of ionization EASI (easy ambient sonic-spray ionization). This technique makes the environment ionization mass spectrometry a more simple tool, as for this study there was no sample preparation, tests were performed directly from the tablet surface. To know the best route of degradation of enalapril maleate formulation, we compared two methods of manufacture of tablets, wet granulation and direct compression. Indicating large differences in degradation profile.The evaluation of the degradation products was performed in parallel using the technique of separation by high performance liquid chromatography with UV detector, showing the comparison of responses of the art EASI-MS and HPLC-UV.Studies were performed according to the studies of the long term stability, thus simulating the stability of enalapril maleate in a compressed and forced degradation study with heat and acid attack, demonstrating the ability of the technique of evaluating the degradation studies forced.