Confocal Raman microspectroscopy is applied to the in situ probing of interfacial processes in pulsed-current copper electrodeposition. This technique provides time-resolved characterization of the vibrational spectra of sulphate ions whenever in solution or adsorbed on the growing electrode. It also confirms the formation of cuprous oxide in the reduction process as the solution pH is increased by proton reduction. Moreover, when the passage of current is terminated, this technique provides evidence for the recombination of copper ions with copper metal to produce cuprous oxide on the outermost branches of the deposit.