Various metal molds are made by an electroforming process. We fabricated a Ni structure using the electroforming process, and evaluated the effects of adding various agents to the trench substrates. The trench substrate was made using a photolithography process. When electrodeposition is applied to the trench substrate, voids are formed in the trench. In this work, void free electrodeposition is achieved by adding certain agents. We investigated the mechanisms of these added agents by performing electrochemical measurements.