NOVELTY - The apparatus comprises a steam methane reformer for reforming methane gas to produce hydrogen/carbon monoxide with a weight ratio of 3:1. Multiple coil type heat exchangers are provided with a pressure swing adsorption and separation unit for separating gas in first and second heat exchangers equipped with a heat supply pipe. The pipe supplies heat to hydrogen/carbon monoxide with a weight ratio of 2:1. A gas supply pipe supplies high purity hydrogen to the pressure swing adsorption and separation device to produce liquefied petroleum synthesized by a Fischer-Tropsch synthesis reactor.    USE - The apparatus is useful for simultaneously producing synthetic liquid such as oil, gasoline, diesel and wax, and electricity.    ADVANTAGE - The apparatus efficiently and simultaneously producing synthetic liquid and electricity with reduced energy consumption, low production cost and reliable operation in a simple manner.    DETAILED DESCRIPTION - The apparatus comprises a steam methane reformer for reforming methane gas to produce hydrogen/carbon monoxide with a weight ratio of 3:1. Multiple coil type heat exchangers are provided with a pressure swing adsorption and separation unit for separating gas in first and second heat exchangers equipped with a heat supply pipe at 200-250 degrees C, where the first heat exchanger has a high-temperature of 600-800 degrees C. The heat supply pipe supplies heat to hydrogen/carbon monoxide with a weight ratio of 2:1. A gas supply pipe supplies high purity hydrogen to the pressure swing adsorption and separation device to produce liquefied petroleum synthesized by a Fischer-Tropsch synthesis reactor. The pressure swing adsorption and separation unit is connected with a fuel cell electric generator to generate electricity. A methane heat exchange feeding line is equipped with the third heat exchanger having a temperature of below 100 degrees C. The heat supply pipe is connected with the electrical generator and the steam methane reformer having a reactant flow rate of 2500-8700 h-1, where the gas in the heat exchangers is purified to high purity hydrogen and to produce synthetic gas using the Fisher-Tropsch synthesis reactor. The reactor is provided with a control area and a synthetic fiber. The second heat exchanger is provided with a synthesis gas supply pipe. The pressure swing adsorption and separation device is made of zeolite, activated carbon or alumina adsorbent having 2-12 carbon. An INDEPENDENT CLAIM is included for a method for simultaneously producing synthetic oil and electricity.