Abstract: The invention concerns demagnetization devices used in particular for demagnetizing vessels or submarines in fixed stations, wherein one embodiment comprises: three sets of conductors for demagnetizing a vessel according to three directions; a direct current generator; an array of capacitors, a bridge switching device, an inductance coil; a switch allowing to select one of the three assemblies of conductors; a servo device for controlling the charge voltage of the array of capacitors; magnetometers; and a screen and keyboard allowing especially to supply a microprocessor with a reference value fixing the value of the desired residual magnetization; the demagnetization consisting of sending into each set of conductors a sequence of discharges, of smaller and smaller intensity and servo-controlled to the value of the remaining magnetization, in order to cause the magnetization to converge towards the desired value.