NOVELTY - Removing sulfur-containing contaminants from a gas stream involves: (a) providing gas stream comprising natural gas, hydrogen sulfide, organic sulfur compounds and carbon dioxide to first absorption unit; (b) providing hydrogen sulfide lean gas stream to second absorption unit; (c) providing first regenerator with the hydrogen sulfide rich absorbent from first absorption unit; (d) providing hydrogen sulfide rich gas to Claus unit comprising Claus furnace and Claus catalytic stage; and (e) providing a second regenerator with absorbent rich in organic sulfur compounds and in carbon dioxide.    USE - Removing sulfur-containing contaminants from gas stream (claimed).    ADVANTAGE - In the process, sulfur-containing contaminants are removed from gas stream in more efficient way. Enrichment process of hydrogen sulfide over carbon dioxide is improved.    DETAILED DESCRIPTION - Removing sulfur-containing contaminants from a gas stream involves: (a) providing a gas stream comprising natural gas, hydrogen sulfide, organic sulfur compounds and carbon dioxide to a first absorption unit, resulting in a hydrogen sulfide lean gas stream and a hydrogen sulfide rich absorbent; (b) providing the hydrogen sulfide lean gas stream to a second absorption unit, resulting in a cleaned gas stream and an absorbent rich in organic sulfur compounds and in carbon dioxide; (c) providing a first regenerator with the hydrogen sulfide rich absorbent from the first absorption unit, to obtain a lean absorbent and a hydrogen sulfide rich gas stream; (d) providing the hydrogen sulfide rich gas to a Claus unit comprising a Claus furnace and a Claus catalytic stage to convert the hydrogen sulfide to obtain sulfur and a Claus tail gas; (e) providing a second regenerator with the absorbent rich in organic sulfur compounds and in carbon dioxide to obtain a lean absorbent and a gas stream rich in organic sulfur compounds and in carbon dioxide; (f) fully oxidizing all sulfur species of the gas stream rich in organic sulfur compounds and in carbon dioxide to obtain a sulfur dioxide rich gas stream; (g) cooling of the sulfur dioxide rich stream to obtain steam, water and a cooled sulfur dioxide rich gas stream; (h) providing a third absorption unit with the sulfur dioxide rich gas stream to obtain a sulfur dioxide rich absorbent and sulfur dioxide lean gas stream; and (i) providing a third regenerator with the sulfur dioxide rich absorbent from the third absorption unit, to obtain a lean absorbent and a purified sulfur dioxide gas stream.