Abstract: The present invention is a unique solder reflow oven useful for annealing electronic parts through convective heating. It has an enclosed chamber with an entrance and an exit. A conveyor is located in the lower part of the chamber for transporting electronic parts from the entrance to the exit, and a diffuser plate is suspended in the upper part of the chamber. The diffuser plate has a central duct and a periphery edge. An entrance heater plate and an exit heater plate are mounted on the periphery edge of the diffuser plate and located proximal to the entrance and the exit of the chamber respectively. An impellar is mounted above the central duct of the diffuser plate for forming in the chamber a multiplicity of circulatory airstreams which are orginated from the impeller and circulating from above the diffuser plate, around the periphery edge of the diffuser plate, then between the diffuser plate and the conveyor and toward a lower central region below the central duct of the diffuser plate.