PURPOSE: To reform liquefied natural gas so as to be suitable for gas turbine fuels excellent in environmental compatibility without generating CO2 by H2 combustion, by reforming liquefied natural gas into H2 and CO2 followed by separating the H2 alone through a H2 separation membrane to accomplish separation of the H2 in high concentrations.

CONSTITUTION: Liquefied natural gas(LNG) is first reformed by a reformer 6 into a gas predominant in H2 and CO, and the CO is subjected to shift reaction with steam in shift reactors 7, 8 to effect reforming into H2 and CO2. Next, the H2 alone in the reformed gas is separated by a H2 separation membrane 9, thus reforming the LNG into a gas turbine fuel. It is preferable that the non-separated gas consisting mainly of CO2 impermeable through the membrane 9 be liquefied by the cold 1 retained by the LNG.