A machine (10) for environmental sanitisation comprising a system of dispensing and nebulisation (12) of a sanitising solution (SS) in an environment (AM) to be sanitised, wherein the sanitising solution, used by the sanitisation machine, is constituted specifically by an aqueous solution of hydrogen peroxide (H2O2) and silver salts or nitrate (AgNO3), and wherein the system of dispensing and nebulisation (12), included in the sanitisation machine, is configured in such a way as to dispense and nebulise the sanitising solution (SS) with a certain concentration, in the environment to be sanitised (AM), comprised between 3 ml/m3 and 6 ml/ m3. Advantageously the system of dispensing and nebulisation (12) of the sanitisation machine (10) comprises a nebuliser assembly (13), of the multi-nozzle type and in particular constituted by four nebulisation nozzles (13), apt to nebulise uniformly, at 360°, the sanitising solution (SS) in the environment (AM) to be sanitised. The sanitisation machine can operate in a totally automatic manner to perform a cycle of complete sanitisation or a cycle of preventive sanitisation, and allows all the various phases of the process of sanitisation of an environment to be programmed and kept under control, thanks to a dedicated program and a practical user interface.