Chamomile, Matricaria recutita L. from family of Asteracae, is a well-known medicinal plant in folk medicine cultivated all over the world. Chamomile essential oil is widely used in pharmaceutical, cosmetic, and food industries. This paper focuses on isolation methods and chemical constituents of essential oils from Matricaria recutita L. in Iran as to optimize these methods and achieving the proper economic procedures. The volatile constituents of Matricaria recutita L. cultivated in Iran were extracted by different methods of extraction by microwave usage, pilot plants and laboratory scale. The oil yields obtained from microwave was 0.08%, laboratory scale 0.06%, pilot 0.06% and pilot with heating element 0.07%. Essential oils were identified by GC and GC/MS. A total of 34 components were identified and significant qualitative and quantitative differences were observed amongst the studied. The main constituents of the essential oils of the studied three different methods were as follows: Microwave were α-bisabolol oxide A (42.3%), chamazulene (15.1%), α-bisabolol oxide B (9.6%), (Z,Z)-farnesol (8.1%) and in laboratory scale were cis-pinocamphone (73.5%), α-bisabolol oxide A (7.9%), in pilot were α-bisabolol oxide A (62.1%), chamazulene (10.2%), (Z,Z)-farnesol (8.3%) and in pilot with heating element were α-bisabolol oxide A (50.5%), E- b - farnesene (12.8%), chamazulene (12.3%) . The best method of extraction was pilot method, because α-bisabolol oxide A (62.1%), chamazulene (10.2%), were major components, which are showing different pharmacological activities like anti-inflammatory, anti-cancer, anti-allergic, a treatment for stress and depression.