Method for melting glass in a melting furnace comprising a melting chamber equipped with n burners, with n ≥ 1 and a preheating installation, method wherein: • raw material to be melted is introduced into the melting chamber, • fuel is burned by means of n burners so as to generate thermal energy for melting the raw material and to obtain the melted glass and a hot stream of smoke having a temperature at the outlet of the melting chamber varying between 1000°C and 1600°C, • the hot stream of smoke coming from the chamber is introduced into the preheating installation, • in a first heat exchanger of the preheating installation, a stream of a first oxidant, called intermediate oxidant, having an oxygen content of 21% vol. or more and containing air, is heated by heat exchange with the hot stream of smoke so as to generate a cooled stream of smoke and a heated stream of intermediate oxidant having a temperature varying between 600°C and 900°C, • in a second heat exchanger of the preheating installation, a stream of a second oxidant, called rich oxidant, having an oxygen content of between 80% vol. and 100% vol. and greater than the oxygen content of the intermediate oxidant is heated by heat exchange with the heated stream of intermediate oxidant, so as to generate a preheated stream of rich oxidant having a temperature of between 400°C and 650°C and a temperate stream of intermediate oxidant having a temperature of between 350°C and 650°C, and • the preheated stream of rich oxidant is provided as oxidizer at n1 of the n burners, called first burners, with 1 ≤ n1 ≤ n, the method being characterised in that: • at least some of the temperate stream of intermediate oxidant is provided as oxidizer at n2 of the n burners, called second burners, with 1 ≤ n2 ≤ n. • raw material to be melted is introduced into the melting chamber, • fuel is burned by means of n burners so as to generate thermal energy for melting the raw material and to obtain the melted glass and a hot stream of smoke having a temperature at the outlet of the melting chamber varying between 1000°C and 1600°C, • the hot stream of smoke coming from the chamber is introduced into the preheating installation, • in a first heat exchanger of the preheating installation, a stream of a first oxidant, called intermediate oxidant, having an oxygen content of 21% vol. or more and containing air, is heated by heat exchange with the hot stream of smoke so as to generate a cooled stream of smoke and a heated stream of intermediate oxidant having a temperature varying between 600°C and 900°C, • in a second heat exchanger of the preheating installation, a stream of a second oxidant, called rich oxidant, having an oxygen content of between 80% vol. and 100% vol. and greater than the oxygen content of the intermediate oxidant is heated by heat exchange with the heated stream of intermediate oxidant, so as to generate a preheated stream of rich oxidant having a temperature of between 400°C and 650°C and a temperate stream of intermediate oxidant having a temperature of between 350°C and 650°C, and • the preheated stream of rich oxidant is provided as oxidizer at n1 of the n burners, called first burners, with 1 ≤ n1 ≤ n, • at least some of the temperate stream of intermediate oxidant is provided as oxidizer at n2 of the n burners, called second burners, with 1 ≤ n2 ≤ n.