Abstract: A process for the direct reduction of iron oxide by blowing into a reduction furnace a reducing gas which is prepared by reforming a mixture of a reduction furnace exhaust gas and a gas mainly composed of methane, which comprises the steps of dividing the gas mainly composed of methane into two branch streams, mixing the first branch stream gas with a part of the reduction furnace exhaust gas and supplying the resulting mixture to the externally heated reformer furnace, to produce a high-temperature reformed gas; mixing the second branch stream gas with said high-temperature reformed gas and during the course to the reduction furnace, subjecting the mixture to endothermic reforming reactions in an after-reactor without external heating, utilizing the sensible heat of the high-temperature mixed gas, controlling the self-reforming reactions so as to lower the temperature and simultaneously adjust the composition of the high-temperature mixed gas, and blowing the reducing gas obtained into the reduction furnace.