Combustion in a porous medium is considered by many researchers as an advanced industrial technology. This type of combustion can have advantages such as greater flammability limit, lower emission rate, higher radiation efficiency and laminar flame speed compared to free flame burners. In this generation, the burners use all three methods of heat transfer, conduction, convection, and radiation due to the fusion of the solid porous medium material. In this study a suitable burner for the free flame burner is designed, constructed and installed. Then, the combustion performance of the porous medium burner was experimentally investigated. This porous medium burner has a fiber structure of FeCralloy (Iron Chromium Aluminum Alloy).The effects of equivalence ratio and firing rate on temperature, porous burner radiation efficiency, pollutant emission rate, residence time and boiler efficiency were investigated. It was found that increasing the firing rate reduced the radiation efficiency of the porous and thermal efficiency of the boilers, as well as the amount of carbon monoxide emission, on the other hand, this increase in firing rates led to an increase in temperature, residence time and nitrogen oxides release rate. Increasing the equivalence ratio also increases the radiation efficiency of the porous burner, thermal efficiency of the boiler, the residence time and the amount of nitrogen oxides released, and, on the other hand, this increasing the equivalence ratio reduces carbon monoxide emissions. The results of the comparison of the performance of the porous medium burner and free flame burner indicate an increase of 9% of the flammability range. The amount of emissions and thermal efficiency of the boiler in the range of common flammability are averaged and compared. The porous medium burner boosts boiler efficiency by 8%, reduces 22 ppm of nitrogen oxides and increases the emission of carbon monoxide by 190 ppm. Also, the design of experiments techniques were used for this research and the results of the research were analyzed from a statistical point of view. The results of signal-to-noise analysis show that the factors of the equivalence ratio and firing rate are the main role for the thermal efficiency target and the carbon monoxide emission rate, respectively and for the target variable, the rate of nitrogen oxide release, both factors of firing rate and equivalence ratio are almost equally effective. Keywords: Porous medium burner, Metal fiber, Premixed combustion, Combustion pollutants, Efficiency, Design of experiments