The present invention relates to a tunnel oven having a baking chamber 4 and a conveyor for carrying items to be baked through the baking chamber 4. The oven 2 comprises an in-direct fired radiant heat source 22, a forced-air radiant heat source 26, the radiant and convective heat source 22a, 26, wherein there is an adjustment means 72, 349, 36, 202, 204, 210 to independently change the atmospheric moisture content in the baking chamber and the quantities of radiant and convective heat, the convective heat being adjustable between 0% and 100% of maximum available forced-air supply into the baking chamber 4.