Carbon capture, utilization, and storage (CCUS) have been attracting much attention as an initiative to achieve carbon neutrality. In the capture and storage strategy, amines are widely used for highly efficient separation and capturing of CO 2 since amines react with CO 2 to form carbamates. In the utilization strategy, CO 2 electroreduction is a promising method to convert CO 2 into value-added compounds because reaction conditions are relatively mild and easily controlled. In this work, toward combining CO 2 capture and storage technologies and CO 2 electroreduction, we focused on amine modification of the electrode surface, in which borondoped diamond (BDD) was chosen as a sustainable electrode material. CO 2 electroreduction using the amine-modified BDD was performed, and an applied potential dependence of the product selectivity was examined. In situ attenuated total reflectance-infrared measurements showed that the peak intensity of the stretching vibration of the carbonyl group at around 1640 cm −1 decreased as applied potentials became more negative. The effect of amine modification of the BDD surface lies in the formation of a C−N bond during CO 2 electroreduction, resulting in the enhancement of the selectivity of CO production up to 8 times compared to the unmodified BDD.