Ethylene oxide production inside a coated wall microreactor is simulated using computational fluid dynamics. This work considers two parallel plates microreactor filled with different cross-sectional shapes network spacers. The Reynolds numbers in this study ranged from 200 to 800. The spacers' cross-sectional shapes are circular, square, and triangular. The results show that using spacers inside the two parallel plates microreactor is effective at Reynolds number higher than 600. The results show that the triangular spacer with α = 45 deg is the best performance among other spacers at a high Reynolds number, increasing 50% in the reactor performance.