Abstract: The invention relates to a magnetically controlled switch with contacts wetted by a conductive liquid. It is characterized in that the wettable contact surfaces of the electrodes are selectively connected to one another by a wettable ferromagnetic moving element covered with mercury which is held solely by the surface tension forces of the mercury. The absence of any polarizing force and the lightness of the moving element enable the switch to operate with a minimal energy consumption and stabilize it against accelerations. Principal application to any low-power circuit and in particular to telephone circuits.