Abstract: The oven according to the invention comprises a plurality of heated superimposed channels and a plurality of rollers for supporting and advancing the ceramic materials, generally tiles, arranged transversely in each channel and closer to the ceiling than to the floor of the channel. Preferably the distance of the roller axes from the channel floor is not less than twice the pitch of the rollers and their distance from the channel ceiling is not more than such pitch. Preferably the channels are each constituted by a plurality of laterally juxtaposed chambers separated by partitions, the rollers extending through the channels without engaging the partitions. The superimposed adjacent channels are preferably separated by hollow slabs and slabs are located above the highest and below the lowest channels, hot gases being introduced into the cavities within the slabs and flowing out through apertures in the slabs to heat the tiles, or electrical resistances are provided in the slabs.