The raising of consciousness of environmental protection makes environmental analysis so important in chemistry. It causes a rapid improvement of environmental analysis techniques. The targets scientists strive for are decreasing analytical time, lower amount of man-made errors and increasing analyzing speed. The techniques in sample pretreatment are also changing every day. The theory, instrumentation and operating method of Accelerated Solvent Extraction (ASE) will introduced in this article. The technique will be compared with other pretreatment techniques. The applications of ASE on other analytical fields and possibility of interfacing with other techniques are illustrated.