The objective of the paper was to design and test various variants of the thermal biomass processing controllers. The process took place in a batch reactor consisting of a metal chamber into which thermal energy was supplied through a diaphgram with the use of a 2 kW power ceramic band heater. The chamber of the reactor along with the heater was thermally insulated. A classic solution of a PID controller and its variety - a robust PID controller, resistant to the object parameters fluctuations was selected for tests. The Linux Debian system and the SciCosLab environment, consisting of graphic SciCos environment were used for the operation of the stand. The system kernel was modified for operation in real time through a RTAI module (Real Time Application Interface). Analysis of the results shows that, a robust controller ensures better quality, which besides a shorter time of response, behaves better in case of the object parameters fluctuations.