Abstract: Device for the electrochemical treatment, in particular localized, of a conducting substrate, which comprises a casing provided with an opening and delimiting a space, an electrode arranged in this space and intended to be connected to one of the terminals of a source of electric current, the conducting substrate being intended to be connected to the other terminal of this source, and an electrolyte inlet and an electrolyte outlet, both communicating with the said space, characterized in that it moreover comprises a body made of absorbent, flexible material which does not conduct electricity and which is permeable to gases and liquids, this body being in contact with the said electrode and closing off the said opening, projecting beyond the latter, a first pump mounted on the said electrolyte inlet and a second pump mounted on the said electrolyte outlet, the flow rate of the second pump being greater than that of the first pump and fixed in relation to that of the first pump, so as to create an underpressure