The invention refers to the field of the rotating discontinuous sterilizers (known as autoclaves) of the horizontal End-Over-End type having baskets with the backpressure sterilization technology.The rain water cycle rotating basket sterilizer of the type comprising a pressurized horizontal cylindrical vessel (2) receiving rotating baskets (8), containers with a product to be sterilized being housed in the baskets, is characterized by the combination of:- stationary process fluid spraying nozzles (22) located on the upper part of the horizontal cylindrical vessel (2)- movable nozzles (23) which, by integrally rotating with said baskets (8), causing water jets to continuously hit a series of predetermined points on the containers receiving the product- means for adjusting the baskets (8) rotation speed- means for adjusting the flow rate and pressure of the process fluid.
