A device for capacitive detection (300;350;400;500) of an object, comprising: - at least one polarization module (200;210;220;230;240;306) configured to polarize at least one measurement electrode at an alternating electrical potential (V g), called working potential, different from a ground potential, at a working frequency; and - measurement electronics configured to measure a signal relating to a capacitance (C oe), called object-electrode capacitance, seen by said at least one measurement electrode, at said working frequency; in which the at least one polarization module (200;210;220;230;240;306) comprises at least one toroidal element (202;212;222;232; 212 1 -212 n), called excitation toroidal element, with a central opening: - provided to be placed around at least one electrical conductor (110;308) electrically connected to said at least one measurement electrode, through the central opening, and - comprising at least one electrical winding (204;214;224 1 -224 3), supplied by an alternating electrical signal, arranged to generate a circular magnetic field in the excitation toroidal element (202;212;222;232;212 1 -212 n) and an axial magnetic field vector potential in said central opening; so as to induce, in said electrical conductor (110;308), an alternating potential difference equal to said working alternating electrical potential (V g) at said working frequency, between an input and an output of said at least one toroidal element (202;212;222;232;212 1 -212 n). - at least one polarization module (200;210;220;230;240;306) configured to polarize at least one measurement electrode at an alternating electrical potential (V g), called working potential, different from a ground potential, at a working frequency; and - measurement electronics configured to measure a signal relating to a capacitance (C oe), called object-electrode capacitance, seen by said at least one measurement electrode, at said working frequency; in which the at least one polarization module (200;210;220;230;240;306) comprises at least one toroidal element (202;212;222;232; 212 1 -212 n), called excitation toroidal element, with a central opening: - provided to be placed around at least one electrical conductor (110;308) electrically connected to said at least one measurement electrode, through the central opening, and - comprising at least one electrical winding (204;214;224 1 -224 3), supplied by an alternating electrical signal, arranged to generate a circular magnetic field in the excitation toroidal element (202;212;222;232;212 1 -212 n) and an axial magnetic field vector potential in said central opening; - provided to be placed around at least one electrical conductor (110;308) electrically connected to said at least one measurement electrode, through the central opening, and - comprising at least one electrical winding (204;214;224 1 -224 3), supplied by an alternating electrical signal, arranged to generate a circular magnetic field in the excitation toroidal element (202;212;222;232;212 1 -212 n) and an axial magnetic field vector potential in said central opening; so as to induce, in said electrical conductor (110;308), an alternating potential difference equal to said working alternating electrical potential (V g) at said working frequency, between an input and an output of said at least one toroidal element (202;212;222;232;212 1 -212 n).