Abstract: This invention concerns a washing machine, particularly for washing out the cages and tanks used in animal laboratories, comprising a wash chamber into which a load of the items to be washed can be inserted and equipped with multiple nozzles and a water collection reservoir situated in the floor of the wash chamber. It is characterised by the fact that it comprises a single hydraulic circuit suitable for carrying out, using the system of supplying water to the load, the entire wash and rinse cycles, without the need for two separate wash and rinse circuits. The object of this invention is also the washing method carried out by this machine.