Supercritical micronization is the process that uses a supercritical solvent, usually carbon dioxide, to close active substances in shells. In this paper, the process of supercritical micronization was characterized as were its theoretical basis and methods of performing it. The supercritical micronization process was divided by the supercritical CO₂ application technique. The division resulted in selecting the micronization process with the supercritical CO₂ applied as a solvent (RESS Rapid Expansion of Supercritical Solution) or as an anti-solvent (SAS Supercritical Anti-Solvent, PGSS Particles from Gas Saturated Solutions, and ASES Aerosol Solvent Extraction System). Any of those processes can be used for the micronization in the food industry. However, until now, the majority of the micronization methods are still tested in laboratories, and only the patented PGSS process was applied on the industrial scale.