in the range 0 3 to 30 ghz or most preferably 900 mhz the unit 9 is shielded so that no hazardous microwave radiation can escape to the surroundings heating in 9 corresponds to step 3 above to conclude the description in each of the three steps the heating of the product is supplied through different electromagnetic phenomena without any physical contact between the actual heating elements u2014 such as coils and electrodes u2014 and the product the cited frequencies above are given to clarify the description it is understood that the proposed multistep method will work also for frequencies that deviate significantly from the stated values it is also understood that the inductive heating in step 1 and 2 must not necessarily be applied through electrically conductive elements inside a product the inductive heating can instead be applied through an electrically conductive material e g a metal form which is in contact with or in close proximity to the product examples of products for which the proposed process can be applied are wood grain and bricks to give an alternative another principal description of the proposed method a schematic illustration of the process is outlined in fig5 a conveyor belt a cart system or a similar arrangement 12 moves the product to the high frequency radio unit 13 which.