MSU-S mesoporous catalyst with [SiO2]/[Al2O3] ratio of 55 was synthesized using tetrapropylammonium hydroxide (TPAOH) as a structure directing agent and hexadecyltrimethylammonium bromide (CTAB) as a surfactant. The catalytic activity of the calcined sample was evaluated for the dehydration of methanol to dimethyl ether (DME) in a vertical fixed bed microreactor at a weight hurly space velocity (WHSV) of 5 hr-1 .Temperature ranged from 230 °C to 380 °C and pressure was kept constant at 1 bar. The catalyst was characterized by XRD; consequently, the mesoporous structure of MSU-S catalyst was verified. The activity, selectivity, and stability of MSU-S catalyst were investigated in a vertical fixed bed reactor. An increase in methanol conversion was observed by increasing temperature. The equilibrium conversion of methanol was almost reached at 380 °C and selectivity decreased from 100% to 97% as temperature rose from 200 °C to 380 °C. The stability of MSU-S (Michigan State University) catalyst was investigated for 12 hr at 380 °C and a stable methanol conversion was observed during the mentioned time.