The extended analysis of influence of the surface hydrogen passivation degree on morphology of mesoporous Ge (PGe) formed by Bipolar Electrochemical Etching technique is reported. It is shown that the high degree of the surface passivation results in formation of the isotropic sponge-like PGe layers, whereas at low degree of the surface passivation the crystallographic “pine-tree-like” pores are obtained. The intermediate passivation results in the “fish-bone” morphology. It should be noted that the last two morphologies were never obtained before and are unique to mesoporous Ge. The electrochemical reactions taking place on Ge during BEE process are identified by analyzing the evolution of the surface potential during the BEE process; the results were interpreted similarly to the cyclic voltametry data. Finally, a general electrochemical model describing the pore formation with different morphologies depending on the surface passivation degree is introduced.