A coal gas supply method converts a carbon carrier in a reactor into a coal gas by the addition of oxygen and feeds the coal gas to fuel consumers. To ensure a continuous fuel supply to the fuel consumers during the coal gasification process, a branch current of the coal gas produced is liquefied and stored. At the same time the oxygen stored in liquid form is drawn from a tank, evaporated and used in the reactor. If there is a breakdown in the coal gasification process, the stored quantity of coal gas is evaporated gradually and fed to the consumers. At the same time, oxygen drawn from an oxygen inlet pipe is liquefied and stored. Instead of coal gas, another fuel gas such as natural gas can also be used.