The present invention relates to novel hydrogenases isolated from novel hyperthermophilic strains belonging to Thermococcus spp., genes encoding the hydrogenases, and methods of producing hydrogen using strains having the genes. According to the hydrogen production methods of the invention, a large amount of hydrogen can be produced merely by culturing the strains in specific culture conditions. Thus, the methods of the invention have advantages in that they are more economic and efficient than existing hydrogen production methods and can produce hydrogen even at high temperature.