In this work the prototype of a combustion chamber for a domestic small-scale furnace with a fuel power of 15 kW for the incineration of biomass pellets from agricultural products like straw and Miscanthus was developed. Because of the low ash melting point of these fuels the incineration is problematical. Therefore the primary air is supplied from above to the fuel bed. In this way slagging and adherence with the grate can be reduced. A part of the work is about adjusting of parameters. To decrease the low carbon content in the ash and reducing of slagging tendencies, primary airflow rate, velocity of the moving grate and fuel power are varied. Furthermore mass balances and energy balances were done, fuel input were explored and the decrease of power due to carbon in the ash was analysed. Primary and secondary airflow rates as well as the dwell time of fuel on the grate were determined respectively. Additionally the gaseous emissions and the total suspended particles were analyzed. Also a clear relationship between ash content in the fuel and the dust in the off-gas could be illustrated.