FIELD: search for fields of oil and gas, study of migrations of fluids in rocks by composition of gas and liquid inclusions. SUBSTANCE: samples of rock are taken, after mechanical or thermo-mechanical outgassing of each sample in vacuum plant mass spectrometric composition of liberated gases is determined by value of ratio of mass to charge. They are separated into groups of paleo-atmospheric, inorganic gases and organic compounds. Presence of structural elements characterized by accumulations of oil and gas is judged by positioning of zones of propagation of liberated gases and by values of concentrations of gases. ANALYZER of composition of sample volatile components includes vacuum chamber which houses whirligig holder of samples, two strikers as minimum to execute strikes on samples for their destruction and liberation of gases from gas and liquid inclusions. Vacuum chamber is connected to group of mass spectrometers including at least two of them and is fitted with drives to rotate whirligig holder and to deliver strikes on sample. ANALYZER is also provided with control unit. EFFECT: enhanced functional efficiency of ANALYZER, improved authenticity of method. 12 cl, 28 dwg, 2 tbl
