PURPOSE: To remove impurities in the oil to be treated effectively by allowing to exhibit separating effect due to static electric force effectively.

CONSTITUTION: In an electrostatic desalting apparatus for removing impurities in the oil to be treated utilizing separating effect of static electric force, at least two pairs of plate grid-shaped high voltage electrode 3, 3' arranged horizontally in a vessel 1, plate grid-shaped earthing electrodes 4, 4', an oil introducing pipe 7 for feeding the oil to be treated into the electric field of the pairs of electrode, a dispersing device 13 of a distributing pipe 6 for deflecting a part of the rising oil to counter direction, and a shielding plate 12 are provided. Thus, the oil to be treated fed to the vessel is disturbed in the electric field formed by at least two pairs of the electrode to prompt agglomeration of water drops by the effect of static electric force, and apparent strength of the electric field is reduced without elevating the electric potential of the pairs of the electrode. By this method, the electrostatic separating effect is exhibited effectively and the impurities in the oil to be treated are removed efficiently.