The aim of this work is to study the photo-Fenton process for removing t-butyl methyl ether (MTBE) in wastewater by utilizing LaFeO3perovskites supported on corundum monoliths. The catalytic properties of monolithic samples containing 10.64 wt% of LaFeO3were tested in the photo-Fenton reaction under atmospheric pressure and temperature, irradiating the structured catalyst with a UV lamp emitting at 254 nm. Reaction products in gas-phase were monitored by continuous analyzers, measuring CO, CO2and O2gaseous concentrations at the photo-reactor outlet. Experimental results evidenced that the final value of total organic carbon (TOC) removal is limited by the consumption of H2O2in liquid phase. Starting from this observation, about 100% of TOC removal was achieved by continuously dosing H2O2during irradiation time. Moreover, experimental data obtained in absence of catalyst, showed a high TOC removal (about 97%) but with a significant formation of CO, due to the occurrence of homogeneous photolysis of MTBE. The use of structured catalyst allowed obtaining total TOC removal, acting on all the intermediates produced in the homogeneous reaction, so inhibiting the formation of CO and leading to complete mineralization of MTBE, to CO2and H2O. The highest photocatalytic performances were obtained at pH equal to 6.7. No formation of sludge in the whole pH range investigated was obtained.