Due to the climate diversity in different parts of Iran, a variety of plants grow across the country, many of them having pharmaceutical applications. At present, only a few companies are producing herbal essence, all of them are technically based on conventional methods of extraction such as steam distillation and others. Because of the current serious concern with respect to the environmental conservation law the use of green technology seems imperative. The supercritical fluid extraction is considered as a practical and procedural method which has become under serious consideration in recent years. For this, an economical analysis is made of herb extractions using a supercritical fluid. The results of such a survey can clarify the new methods to be of great concern. The aim of this paper is to present the feasibility studies of supercritical fluid extraction units used for producing a different plant extract and especially that of rosemary.