A machine (1) and a method for the treatment of hazardous medical waste； the waste is fed in a treatment chamber (4) defined inside a cylindrical containing body (3) which is mounted so as to rotate around a rotation axis (5)； the waste is shred by means of a shredding device (9) which is arranged inside the treatment chamber (4)； at the end of shredding the vacuum is generated and maintained inside the treatment chamber (4) for a first time interval (T1 )； at the end of the first time interval (T1 ) the vacuum generation is interrupted and vapour under pressure is fed into the treatment chamber (4) for a second time interval (T2)； and at the end of the second time interval (T2) the vapour feeding is interrupted and the vacuum is generated and maintained again inside the treatment chamber (4) for a third time interval (T3).
