Cylinder-shaped autoclave comprising a light-in-structure separating compartment and preferably rectangular in shape, designed to host the baskets for the products to be processed. The separating compartment, lower in volume as compared to the cylinder-shaped autoclave and preferably rectangular in shape, reduces the volume to be heated and later cooled, with remarkable energy saving. Said compartment has a double worthiness in that it can be introduced and implemented in already existing autoclaves, besides being an integral part of those constructed ex-novo. When the process is activated, the pressure set ensures that the internal pressure inside the separating compartment is the same as the external pressure directed towards the supporting walls. By so doing, the compartment's structure is not affected by differing pressures. The above balance is made possible by means of at least one pressure sensor.
