Even though combustion has been studied for a long time, however, due to complex essence of combustion which is a combination of different physical and chemical phenomena, there are still a lot of questions which should be addressed to improve efficiency of combustion systems such as internal combustion engines. Methane is one of the fuel which can be replaced to the normal fossil fuels such as gasoline and diesel. In this study laminar flame of a methane and air is studied in a freely propagating combustion tube. Different phenomena regarding to laminar flame such as laminar flame speed is studied. Subsequently, preheating zone, reaction zone and secondary reaction zone are studied and their thickness are reported. Finally, to understand the effect of operating conditions, parametric study of equivalence ratio and initial pressure are performed. Results showed that the laminar flame speed is maximum around the stoichiometric air and methane mixture. Also, with increasing the initial pressure, the laminar flame speed reduced monotonically.