The invention relates to a process for methanol synthesis comprising the steps of providing a syngas feed stream comprising hydrogen and a mixture of carbon dioxide and carbon monoxide, wherein carbon dioxide represents from 1 to 50 mol % of the total molar content of the feed stream, carbon monoxide is contained from 0.1 to 85 mol % of the total molar content, and H2 is comprised from 5 to 95 mol % of the total molar content of the feed stream; providing an indium oxide catalyst selected from a bulk catalyst and a supported catalyst comprising indium oxide (In2O3) as the main active phase; putting in contact said stream with said catalyst at a reaction temperature of at least 373 K (99.85° C.) and under a pressure ranging of at least 1 MPa; and recovering the methanol effluents. The invention also relates to an indium oxide based catalyst.