An apparatus is disclosed which can shape fruits and root and tuberous vegetables. The sequence of one or more previously entered characters is used to select a character assignment matrix. By adjusting the gap between the product and the heat source, it is possible to control the source temperature in such a manner that produces the desired product temperature and wavelength of radiation. Further, an amount of output current of differentiation form is not affected by external factors such as voltages, processes, temperatures, and so on.