Abstract: A readily portable apparatus for roasting, drying or otherwise treating grain or other similar particulate material on a continuous fully controlled basis. The material is metered into one end of a revolving drum containing structure for cascading the material through a high temperature gas stream generated by a heating device carried at the other end of the drum. The material gradually traverses the length of the drum while being subjected to such cascading and heating, and is then extracted or discharged out of the other end of the drum. The drum may be tilted a few degrees from the horizontal to provide precise control of the rate and time of traverse of the material through the drum.For purposes of quick and convenient access to the interior of the drum, the heating and material extracting devices are mounted on a hinged cover at the discharge end of the drum.