Abstract: An oven for continuous cooking of products carried upon a open mesh wire conveyor provides the impingement of a cooking vapor from air discharge structure having ports arrayed above and below the conveyor. The discharge ports extend laterally of the conveyor and communicate with upper and lower plenums each charged by blower fans which draw cooking vapor from low pressure corridors alongside the product conveyor. Gas, electric or thermo fluid heaters are disposed in the corridors. The discharge ports are in slot form disposed about the apex of a Vee shaped riser spaced from the adjacent riser to provide a low pressure flow channel communicating with the corridors giving a rapid velocity change of the cooking vapor from turbulent to a less turbulent flow. The distance for vapor travel between the upper discharge ports and the product carrying conveyor is variable. Temperature and moisture content of the process vapor can be changed to suit cooking conditions.