Preform heating device able to perform a precise and strongly localised heating of the preforms before the blow moulding phase of the plastic bottle or container production process. This device has an innovative construction configuration, thus allowing high efficiency thanks to the significant reduction in the energy required to reach the project temperatures in the heating element in a very rapid way. The inductor does not heat the preform directly, but takes to the temperature set, through the concentration of the magnetic flow, generated by the passage of current, a conductor material of a particular form that, by irradiation and convection, in turn heats the PET.