The present invention is a process for converting methane to methanol, comprising: feeding methane and gaseous air or oxygen or gaseous air enriched with oxygen to a reactor under an elevated pressure; said reactor having an internal surface, made of silica or coated with silica, surrounding a zone in which said gases react; and reacting said gases in said reaction zone at an elevated temperature at conditions effective to produce methanol and for valuable oxygenates. Advantageously the internal surface is made of quartz or coated with quartzAdvantageously the internal surface, made of silica (advantageously quartz) or coated with silica (advantageously quartz), is treated with HF before the conversion of methane to methanol.Advantageously the reaction is carried out in the absence in said reaction zone of any added material which measurably affects the rate of the reaction or the yield of the product.Advantageously the reactor is operated under a pressure from 1 to 7.5 MPa.Advantageously the reactor is operated at a temperature from 300° C. to 600° C.Advantageously the reactor is operated at a residence time from 0.1 to 100 s.Advantageously the reactor is operated at a methane to oxygen molar ratio from 1 to 50.The present invention also relates to a reactor having an internal surface made of silica (advantageously quartz) or coated with silica (advantageously quartz).