For the optimal layout of a Fluidized bed combustion, the combustion behaviour of the fuel used plays an important role. The pilot combustion chamber with circulating atmospheric fluidized bed combustion introduced in the essay serves to investigate the combustion behaviour of various kinds of brown coal. Beyond that, the combustion chamber illustrates the processtechnical questions about the operating of fluidized bed combustion. This essay reports on operational results during the combustion of selected kinds of coal.