In a hot isostatic pressing (HIP) method, the component to be treated, affected by imperfections, like porosity, cracks and cavities in its structure, is placed into a container together with non-metallic material in form of powder or grains having size greater than the porosity and the cracks and imperfections of the component. During the HIP process, the non-metallic material presses on the whole surface of the embedded component in order to generate a combination of temperature and forces capable to reduce defects, embedded and not embedded, in the component itself. The component is not contaminated during the process thus allowing easily removal of the non-metallic material by a simple operation of mechanical cleaning or chemical washing.