In the present paper, effects of pre-heated walls/plates on microthrusters performance are studied using a DSMC/NS solver. Three microthruster configuration types are studied. Type 1 is a cold gas microthrster. Microthruster type 2 has pre-heated walls. Pre-heated plates are inserted inside the chamber of microthruster type 3. It is observed that in mi- crothruster type 2 the flow is accelerated and the specific impulse is elevated. However, by insertion of the pre-heated plates in microthruster type 3, viscous effects have stronger nega- tive influence and the thrust is decreased. By implementing temperature gradients on walls in type 2 and on plates in type 3, it is observed that a higher temperature gradient enhances performance parameters of microthruters. Among all types of microthrusters, microthruster type 2 with pre-heated walls has the highest thrust and specific impulse. Microthruster ty- pe 3 with a temperature gradient of 300-500K has the minimum thrust due to a considerable decrease in the mass flow rate.