A baking oven has a baking chamber in which plate members carrying the baking good are stepwisely conveyed along an endless path. The baking chamber has a charging and discharging opening through which a branch of this endless path is fed to a charging and discharging station located outside of the baking chamber. Hot air is blown into the baking chamber by means of a blower. In order to prevent that the hot atmosphere within the baking chamber escapes through the charging opening, this opening can be closed by a closure means actuated in synchronism with the steps of movement of the plate members. Further in synchronism with this actuation, a change-over means is actuated which guides the hot air either into the baking chamber or into a by-pass-channel leading back to the blower.