Provided are a useful hydrocarbon production method and a useful hydrocarbon production device using methane-containing hydrocarbon and carbon dioxide which are easily obtainable source materials and can efficient produce over a long period. The present invention provides a useful hydrocarbon production method including: a dry reforming step for generating a first gas containing carbon monoxide and hydrogen from a mixed gas containing a methane-containing hydrocarbon and carbon dioxide; a useful hydrocarbon generating step of generating a second gas containing a useful hydrocarbon from the carbon monoxide and the hydrogen in the first gas; and a recycling step of separating a carbon dioxide-containing gas from the second gas and supplying the carbon dioxide-containing gas to the dry reforming step.