Recently, hydrogen has been paid attention as a clean energy because hydrogen has little environmental load and high energy conversion efficiency. However, hydrogen must be in high concentration when it is used for energy source such as fuel cells. In this study, we propose a simple hydrogen refinement method utilizing the Soret effect that the concentration gradient increases with the increase of the temperature gradient. We fabricated the device that focused on optimizing a single element of the network device manufactured in a previous study. In this study, we prepare several single element devices using experiments and CFD analysis. In the experiments, we measured two gases that were reduced concentration and increased concentration. In the analysis, we compared the hydrogen concentration at the outlet and checked the condition of re-mixing from velocity vectors and contour diagram. From the experimental results, the concentration improvement of about 0.1% was confirmed as the experimental value, and it was 1/10 of the theory value. From the CFD analysis results, the concentration improvement of 0.38% was confirmed in the small angled device, and the effectiveness was confirmed compared with the basic pattern.