This paper presents work progress of advanced control development achieved on a prototype 100kW biomass-fired boiler. The aim of the research was to develop a complex control system, which provides both the basic boiler heating performance control based on the actual consumption and the optimization of operating conditions using advanced control algorithms. Thus, the resultant control system should ensure these main control tasks, i.e. to provide the desired boiler power achieved with the minimal fuel consumption and simultaneously minimal operation environmental impacts as far as they are achievable. This research is carried out in the cooperation with the company Fiedler Zdenek Ltd. and under the support of the Technology Agency of the Czech Republic.