A baking oven including an oven muffle which includes at least one thermal heating element and which can be heated to various operational temperatures, i.e. a standard baking and roasting temperature and a high cleaning temperature (pyrolysis). The baking oven also includes a cooling fan arranged downstream from a ventilation shaft in order to guide heated air which is formed away from the inside of the baking oven to the outside thereof. According to the invention, at least one part of the ventilation shaft can be automatically adjusted according to various characteristics of the fan to form various cross-section flows by operation of a freely pivotable flap, in order to dispense with cumbersome conventional control measures.