A device for handling an absorbent rod for controlling a nuclear reactor, preferably a sodium-cooled fast-neutron reactor, comprising: - an upper motor compartment positioned on the closing slab of the reactor vat, enclosing motorized means (2a, 2b) for transmitting control for the displacements of a first stem known as the rod control stem, - said rod control stem with its upper part extending in said motor compartment and its lower part extending in a guide sheath extending inside said vat, crossing a cavity of the closing slab of the reactor vat, and - a device for gripping absorbent rod known as a gripper fastened to the lower end of said rod control stem, said gripper being able to seize the upper end of an absorbent rod arranged in the extension of and in alignment with the rod control stem, characterized in that it comprises: - a sealed static confinement chamber made of non-magnetic material arranged inside said upper compartment, in the form of a shroud, comprising a side wall of revolution (5a, 5b), preferably cylindrical, open at its base fastened in a sealed manner to the closing slab of the reactor vat around the cavity of said closing slab crossed by said guide sheath, - a first synchronous magnetic coupling system for transmitting linear translational movement without mechanical contact, comprising: - a first outer component (6a-1) comprising a block of permanent magnet(s), preferably consisting of alternating permanent magnets separated by soft ferromagnetic elements, said block being arranged inside said upper motor compartment outside said confinement chamber, and able to be vertically translated, and - a first inner component (6a-2) comprising at least one soft ferromagnetic element, arranged inside said confinement chamber, integral with the upper part of said rod control stem, the magnetic coupling force of said first outer component (6a-1) and said first inner component (6a-2) making it possible, when the first outer component (6a-1) is displaced in vertical translation, for said first inner component (6a-2) and the rod control stem to follow a displacement in said vertical translation, - said motor compartment comprising first motorized mechanical means for transmitting vertical translational displacements of said first outer component (6a-1) of said first magnetic coupling system.. - an upper motor compartment positioned on the closing slab of the reactor vat, enclosing motorized means (2a, 2b) for transmitting control for the displacements of a first stem known as the rod control stem, - said rod control stem with its upper part extending in said motor compartment and its lower part extending in a guide sheath extending inside said vat, crossing a cavity of the closing slab of the reactor vat, and - a device for gripping absorbent rod known as a gripper fastened to the lower end of said rod control stem, said gripper being able to seize the upper end of an absorbent rod arranged in the extension of and in alignment with the rod control stem, - a sealed static confinement chamber made of non-magnetic material arranged inside said upper compartment, in the form of a shroud, comprising a side wall of revolution (5a, 5b), preferably cylindrical, open at its base fastened in a sealed manner to the closing slab of the reactor vat around the cavity of said closing slab crossed by said guide sheath, - a first synchronous magnetic coupling system for transmitting linear translational movement without mechanical contact, comprising: - a first outer component (6a-1) comprising a block of permanent magnet(s), preferably consisting of alternating permanent magnets separated by soft ferromagnetic elements, said block being arranged inside said upper motor compartment outside said confinement chamber, and able to be vertically translated, and - a first inner component (6a-2) comprising at least one soft ferromagnetic element, arranged inside said confinement chamber, integral with the upper part of said rod control stem, the magnetic coupling force of said first outer component (6a-1) and said first inner component (6a-2) making it possible, when the first outer component (6a-1) is displaced in vertical translation, for said first inner component (6a-2) and the rod control stem to follow a displacement in said vertical translation, - said motor compartment comprising first motorized mechanical means for transmitting vertical translational displacements of said first outer component (6a-1) of said first magnetic coupling system..