Abstract: An apparatus for processing of material, the apparatus comprising: a compartment for accommodating said material during processing, said compartment having at least one wall, an inlet for receiving the material to be processed and an outlet for material once processed to exit the compartment; and a radiation source for directing electromagnetic radiation into the compartment through a portion of the compartment wall that is at least partially transparent to the radiation, the radiation being microwave or radio frequency (RF) electromagnetic radiation; wherein the apparatus is configured to place at least some of the material in the compartment in contact with the at least partially transparent portion of the compartment wall through which the radiation is admitted to the compartment.