An apparatus for recovering and regenerating a refrigerant in an air conditioning system, said apparatus comprising: - a first and a second recovery and regeneration circuits (10, 20) arranged to treat selectively a first or a second refrigerant recovered from said air conditioning system; wherein said first and said second recovery and regeneration circuits (10, 20) comprise each: - a recovery duct (11, 21) and a delivery duct (12, 22) arranged to connect said recovery and regeneration circuit with said air conditioning system, respectively arranged to recover a used refrigerant from said air conditioning system and to deliver a regenerated refrigerant into said air conditioning system; - a compressor (13, 23) arranged to compress said used refrigerant; - an evaporator arranged to separate impurities from said used refrigerant coming from said air conditioning system, in order to obtain a regenerated refrigerant, - a vacuum pump associated with said evaporator; - a condenser (14, 24) arranged downstream of said evaporator configured to condense said regenerated refrigerant; - a reservoir (18, 28) for collecting said regenerated refrigerant and a new refrigerant; - a program means arranged to activate selectively said first and second recovery and regeneration circuits (10, 20) responsive to the choice of a user between said first or said second refrigerant as used refrigerant to recover and regenerate; wherein said first and said second recovery and regeneration circuits (10, 20) comprise, furthermore, a valve means (15, 25) on said recovery duct (11, 21) and a pressure measuring means (16, 26) arranged upstream of said valve means (15, 25); wherein said program means is configured to operate said pressure measuring means (16, 26) for causing selectively said valve means (15, 25) to open and close, in such a way that when a user selects by said program means said first or said second refrigerant, said pressure measuring means (16, 26) measures a pressure in said first or in said second circuit (10, 20) that determines a correct or wrong choice of refrigerant by the user and said program means respectively opens or stops said valve means (15, 25). - a first and a second recovery and regeneration circuits (10, 20) arranged to treat selectively a first or a second refrigerant recovered from said air conditioning system; wherein said first and said second recovery and regeneration circuits (10, 20) comprise each: - a recovery duct (11, 21) and a delivery duct (12, 22) arranged to connect said recovery and regeneration circuit with said air conditioning system, respectively arranged to recover a used refrigerant from said air conditioning system and to deliver a regenerated refrigerant into said air conditioning system; - a compressor (13, 23) arranged to compress said used refrigerant; - an evaporator arranged to separate impurities from said used refrigerant coming from said air conditioning system, in order to obtain a regenerated refrigerant, - a vacuum pump associated with said evaporator; - a condenser (14, 24) arranged downstream of said evaporator configured to condense said regenerated refrigerant; - a reservoir (18, 28) for collecting said regenerated refrigerant and a new refrigerant; - a recovery duct (11, 21) and a delivery duct (12, 22) arranged to connect said recovery and regeneration circuit with said air conditioning system, respectively arranged to recover a used refrigerant from said air conditioning system and to deliver a regenerated refrigerant into said air conditioning system; - a compressor (13, 23) arranged to compress said used refrigerant; - an evaporator arranged to separate impurities from said used refrigerant coming from said air conditioning system, in order to obtain a regenerated refrigerant, - a vacuum pump associated with said evaporator; - a condenser (14, 24) arranged downstream of said evaporator configured to condense said regenerated refrigerant; - a reservoir (18, 28) for collecting said regenerated refrigerant and a new refrigerant; - a program means arranged to activate selectively said first and second recovery and regeneration circuits (10, 20) responsive to the choice of a user between said first or said second refrigerant as used refrigerant to recover and regenerate; wherein