The main objective of this work it is to highlight the possibilities of substitution of all or a part of the current technology with technology of extracting by using microwave energy and to highlight the existence differences in quality of the extracted oils for different temperatures using as solvent the ethyl alcohol. In this paper is studied the essential oil extraction method that was performed from the leaves, stems and roots of celeriac milled, by using ethanol as extraction solvent. In a series of experiments were examined the effect of process parameters - initial temperature, the temperature of extraction, the particle size of celery used - the rate of extraction. The results showed a significant increase in the rate of extraction of celery with decreasing particle size analyzed. A similar effect was observed with increasing solvent flow rate and the temperature decrease.