A real-time surface observation system with a channel flow double electrode was developed for analysis of initiation of corrosion pits on copper during anodic polarization. In this system, a video of the surface morphology of a working electrode (WE) is taken by an optical microscope combined with a charge-coupled device camera, and the metallic ions dissolved from the WE can be detected by arranging a detecting electrode (DE) downstream of the WE. It was confirmed that the initiation of micrometer-size pits on copper corresponded to the oscillation of dissolution current of cuprous ions. (C) 2017 The Electrochemical Society. All rights reserved.