The present study examined how to minimize the influence of the anodic reaction products by using an ion-exchange membrane to separate the cathode and anode compartments and by changing the anode electrolyte composition. The current efficiency is maintained at 100% for more than 6 times longer period compared to the conventional plating method using a one-compartment cell. The present iridium plating is also superior in crack formation. The addition of glycerol is effective in reducing the crack formation not only in freshly prepared plating baths but also in plating baths used for long periods. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3432336] All rights reserved.