Machine for sterilising containers comprising: a rotary carousel provided with a plurality of treatment stations of the containers, in each of said treatment station being arranged a dispensing nozzle; an isolator configured for separating the rotary carousel from the external environment; means for generating an air flow; a vaporisation device configured to generate a mixture of air, water vapour and evaporated sterilising agent, said vaporisation device comprising a first inlet communicating with said means for generating an air flow so as to feed air into the vaporisation device, a second inlet in communication with supply means configured so as to supply a watery composition containing a liquid sterilising agent inside the vaporisation device and an outlet through which said mixture exits, wherein it comprises: a post-heating unit operatively active on said mixture so as to maintain the temperature thereof above a dew point temperature, said post-heating unit being placed immediately upstream of a treatment chamber of the container to be sterilised and being structurally and functionally separate from said vaporisation device; a rotary distributor arranged inside the isolator and configured to receive the mixture from the post-heating unit and to distribute the mixture towards the dispensing nozzles of the treatment stations, said vaporisation device being arranged in a lateral zone of the rotary carousel and wherein said post-heating unit being located in proximity of the rotary carousel. a rotary carousel provided with a plurality of treatment stations of the containers, in each of said treatment station being arranged a dispensing nozzle; an isolator configured for separating the rotary carousel from the external environment; means for generating an air flow; a vaporisation device configured to generate a mixture of air, water vapour and evaporated sterilising agent, said vaporisation device comprising a first inlet communicating with said means for generating an air flow so as to feed air into the vaporisation device, a second inlet in communication with supply means configured so as to supply a watery composition containing a liquid sterilising agent inside the vaporisation device and an outlet through which said mixture exits, wherein it comprises: a post-heating unit operatively active on said mixture so as to maintain the temperature thereof above a dew point temperature, said post-heating unit being placed immediately upstream of a treatment chamber of the container to be sterilised and being structurally and functionally separate from said vaporisation device; a rotary distributor arranged inside the isolator and configured to receive the mixture from the post-heating unit and to distribute the mixture towards the dispensing nozzles of the treatment stations, said vaporisation device being arranged in a lateral zone of the rotary carousel and wherein said post-heating unit being located in proximity of the rotary carousel. a post-heating unit operatively active on said mixture so as to maintain the temperature thereof above a dew point temperature, said post-heating unit being placed immediately upstream of a treatment chamber of the container to be sterilised and being structurally and functionally separate from said vaporisation device; a rotary distributor arranged inside the isolator and configured to receive the mixture from the post-heating unit and to distribute the mixture towards the dispensing nozzles of the treatment stations, said vaporisation device being arranged in a lateral zone of the rotary carousel and wherein said post-heating unit being located in proximity of the rotary carousel.