Abstract: The behaviour of the water on and near the electrode surface in 1.0 mol·dm~(-3) NaF were studied using in-situ FTIR reflection-absorption spectroscopy and cyclic voltammetry. Two mechanisms are proposed to explain the change of water signal in the potential range -0.7 to -0.3 V(vs. SCE)——the change of ordered state of the water molecules near electrode and the formation of adsorbed hydrogen at the cost of the water in the thin layer solution. In the potential range -0.3 to 0.4 V, the orientation of adsorbed OH~- is thought to change from being parallel t perpendicular to the electrode surfacewith in creasing potential. In the range 0.4 to 0.8 V, the slight decrease of water ignal is attributed to thee consum ption of adsorbed OH~- on the formation of Pt-OH on the electrode.