As the atmospheric carbon dioxide concentration increases by huge use of fossil fuels, the global warming is recognized as much serious problem in recent. To solve the problem, various researches on carbon capture utilization storage (CCUS) have been conducted by many researching groups. Among them, carbon utilization via electrochemical conversion of carbon dioxide is considered as one of the essential technologies because it can remove the carbon dioxide as well as convert it into the useful products such as CH₄, CH₃OH, CO and HCOOH. However, the electrochemical conversion usually suffers from huge energy losses due to the high overpotential originated from chemical stability of carbon dioxide. Therefore, the highly active catalyst should be required to realize the electrochemical conversion of carbon dioxide. Currently, various transition metals were mainly used as catalysts for the electrochemical carbon dioxide conversion to produce formic acid. Among them, the tin has been considered as a promising catalyst because it has high conversion efficiency and low prices. In this work, porous tin catalyst was fabricated by electrodeposition and following annealing process. In order to obtain the large electrochemical surface area, the roughness was controlled by varying the deposition current density. The field emission scanning electron microscope analysis confirmed the formation of porous tin catalyst deposited at highly negative current density. The roughness factor of the catalysts was measured by performing the cyclic voltammetry in 0.1 M NaHCO­₃ with changing the scan rate. The deposited porous tin catalyst was used as cathode for electrochemical carbon dioxide conversion in H-type cell which was separated by proton conducting membrane. To characterize the reaction products both of liquid and gas chromatography were used. The obtained results indicated that the Faradaic efficiency to produce formic acid had significant relationship with the catalyst roughness.