This paper analytically investigates the reaction phenomenon in micro-combustors using a two-dimensional model. The length of micro-combustor is considered at finite length that makes a better physical model than other works. The micro-combustor medium is divided into three integral zones composed of preheat, reaction and post flame where the governing equations are solved using the matching conditions of neighboring zones. The reaction zone thickness is considered as a variable and predicted by an iterative solution. In order to validate the model, normalized magnitude of maximum temperature is compared with published computational data for different values of Peclet number that shows an acceptable agreement that confirms the accuracy of the predicted data. Since a higher wall temperature causes the reaction to be faster, increasing the normalized wall temperature will result to reduce reaction zone thickness.