An electric power generation/hydrogen production combination plant comprises a feed water pump, a feed water heater arranged upstream relative to the feed water pump to heat feed water, a reformer for producing formation gas containing hydrogen by processing at least one raw material selected from the group consisting of methanol, ethanol and dimethylether, using steam, an intermediate loop for circulating a thermal medium in order to supply the heat of steam generated by a steam generator to the reformer, an intermediate heat exchanger for transmitting the heat of the steam by way of the intermediate loop and a heating outlet pipe of intermediate heat exchanger connected to the heating outlet of the intermediate heat exchanger and the feed water heater to heat feed water.