Voltammetry, Electrochemical Impedance Spectroscopy (EIS), Rotating Ring-Disk Electrode techniques (RRDE), Electrochemical Quartz Crystal Microbalance (EQCM) measurements, and in-situ Raman Spectroscopy were applied to investigate the anodic behaviour of Mn in 1 M NaOH solution over a wide potential range. Prior to these experiments, for EQCM, an improved plating bath was designed for coating the thin gold electrode of the quartz sensor with Mn. The results obtained revealed clearly that various oxides, depending on the electrode potential, cover the electrode surface. The oxidation–reduction processes between these different oxides and the associated exchange of species with the solution constitute the main characteristic of this electrode. When the Mn electrode is left in 1 M NaOH solution, it becomes spontaneously passive through two consecutive steps.