Cooking oven comprising: - a cooking chamber wherein foodstuffs can be placed for being cooked, comprising an upper wall; - a heating device for heating the internal of said cooking chamber; - a suction wall separating said cooking chamber from a heating chamber containing, at least partially, said heating device; - a centrifugal fan, positioned in said heating chamber and configured for circulating an airflow through said cooking chamber and said heating chamber; wherein said suction wall comprises a suction mouth facing a central region of said centrifugal fan, wherein said cooking oven comprises: - a cleaning system comprising a washing/rinsing liquid introduction system configured for taking washing/rinsing liquid within the cooking chamber and provided with an outlet positioned in said upper wall of said cooking chamber, wherein said cooking oven comprises: - a diverting element configured for receiving a liquid exiting said outlet of said washing/rinsing liquid introduction system and for spreading it on said suction wall so as to form a liquid film on it, which is taken by gravity into said suction mouth, wherein said diverting element comprises: - an inlet opening facing said outlet of said washing/rinsing liquid introduction system, and - an outlet opening positioned in proximity to said suction wall, characterized in that said diverting element comprises: - a sloped wall configured for guiding liquid (900, 920) coming from the inlet opening to the outlet opening by gravity. - a cooking chamber wherein foodstuffs can be placed for being cooked, comprising an upper wall; - a heating device for heating the internal of said cooking chamber; - a suction wall separating said cooking chamber from a heating chamber containing, at least partially, said heating device; - a centrifugal fan, positioned in said heating chamber and configured for circulating an airflow through said cooking chamber and said heating chamber; wherein said suction wall comprises a suction mouth facing a central region of said centrifugal fan, wherein said cooking oven comprises: - a cleaning system comprising a washing/rinsing liquid introduction system configured for taking washing/rinsing liquid within the cooking chamber and provided with an outlet positioned in said upper wall of said cooking chamber, - a cleaning system comprising a washing/rinsing liquid introduction system configured for taking washing/rinsing liquid within the cooking chamber and provided with an outlet positioned in said upper wall of said cooking chamber, wherein said cooking oven comprises: - a diverting element configured for receiving a liquid exiting said outlet of said washing/rinsing liquid introduction system and for spreading it on said suction wall so as to form a liquid film on it, which is taken by gravity into said suction mouth, - a diverting element configured for receiving a liquid exiting said outlet of said washing/rinsing liquid introduction system and for spreading it on said suction wall so as to form a liquid film on it, which is taken by gravity into said suction mouth, wherein said diverting element comprises: - an inlet opening facing said outlet of said washing/rinsing liquid introduction system, and - an outlet opening positioned in proximity to said suction wall, - an inlet opening facing said outlet of said washing/rinsing liquid introduction system, and - an outlet opening positioned in proximity to said suction wall, characterized in that said diverting element comprises: - a sloped wall configured for guiding liquid (900, 920) coming from the inlet opening to the outlet opening by gravity. - a sloped wall configured for guiding liquid (900, 920) coming from the inlet opening to the outlet opening by gravity.