One of the applications of nano-carbon is a support material of platinum (Pt) catalyst for fuel cells. In this study, the nanocarbon was successfully synthesized by in-liquid plasma in ethanol. The synthesized nano-carbon was characterized by the transmission electron microscope and the Raman spectroscopy. Moreover, the nano-carbon was applied to a support material of Pt catalyst for a proton exchange membrane fuel cell. The formation of the Pt particles on the nano-carbon was also carried out using the in-liquid plasma. The formed Pt/nano-carbon worked as a catalyst of the fuel cell. The fuel cell, fabricated with the Pt/nano-carbon catalyst, generated the maximum output power of 580 mW.