The growing demand for electric power, the relative increase of electrical wirings and the achievement of electronics in household appliances and in all technological sectors have generated exposure of living beings to low and high frequencies electromagnetic fields. Previous research regarding the effects of electromagnetic fields on human health have given contrasting results. However, some effects on biological systems have been clearly evidenced. The aim of this work was to investigate the electromagnetic fields effects on simple organic systems such as neuronal-like cells and typical proteins such as haemoglobin, bovine serum albumin, myoglobin, that have important functions in human metabolism. FTIR spectroscopy and fluorescence spectrophotometry were used to detect the effects of electromagnetic fields on cells and proteins. It was proved that 50 Hz electromagnetic fields and microwaves can alter the proteins' secondary structure and some cellular functions. These results suggest to plan further research regarding devices or bioprotectors that can shield electromagnetic fields.