The utilization of boron doped diamond (BDD) as an electrode material for the electrochemical reduction of CO2 has been studied in recent decades. Its stability and ability to suppress hydrogen evolution makes it an attractive choice for the electrochemical reduction of CO2. It has been confirmed that, when using a bare BDD electrode, very high selectivity and productivity can be achieved in the production of formic acid. Moreover, by modifying the surface of a BDD electrode with copper (Cu) particles, we have been able to produce compounds with a high number of carbon atoms. In this article, we summarize the results of our work on the electrochemical reduction of CO2 using BDD electrodes, with the specific aim of the producing compounds with a high number of carbon atoms.