A differential transformer magnetic permeability sensor comprising: a substrate; at least one drive coil (41, 42); a plurality of electronic components including an oscillation circuit that is connected with the at least one drive coil and generates drive current to be applied to the at least one drive coil; a first differential coil which is disposed at a side of a first surface of the substrate and in which an induced voltage is generated when the at least one drive coil is driven by the drive current; a second differential coil which is disposed at a side of a second surface opposite to the first surface of the substrate and connected with the first differential coil, and in which an induced voltage is generated when the at least one drive coil is driven by the drive current; a first interconnection pattern that is located on the first surface and allows the first differential coil to serve as a reference coil and the second differential coil to serve as a sensing coil; and a second interconnection pattern that is located on the second surface and allows the second differential coil to serve as a reference coil and the first differential coil to serve as a sensing coil, wherein the electronic components are provided in either the first interconnection pattern or the second interconnection pattern, the electronic components: are provided in the first interconnection pattern but are not provided in the second interconnection pattern to enable a circuit based on the first interconnection pattern in which the first differential coil serves as a reference coil and the second differential coil serves as a sensing coil, and the electronic components are provided in the second interconnection pattern but are not provided in the first interconnection pattern to enable a circuit based on the second interconnection pattern in which the second differential coil serves as a reference coil and the first differential coil serves as a sensing coil. a substrate; at least one drive coil (41, 42); a plurality of electronic components including an oscillation circuit that is connected with the at least one drive coil and generates drive current to be applied to the at least one drive coil; a first differential coil which is disposed at a side of a first surface of the substrate and in which an induced voltage is generated when the at least one drive coil is driven by the drive current; a second differential coil which is disposed at a side of a second surface opposite to the first surface of the substrate and connected with the first differential coil, and in which an induced voltage is generated when the at least one drive coil is driven by the drive current; a first interconnection pattern that is located on the first surface and allows the first differential coil to serve as a reference coil and the second differential coil to serve as a sensing coil; and a second interconnection pattern that is located on the second surface and allows the second differential coil to serve as a reference coil and the first differential coil to serve as a sensing coil, wherein the electronic components are provided in either the first interconnection pattern or the second interconnection pattern, the electronic components: are provided in the first interconnection pattern but are not provided in the second interconnection pattern to enable a circuit based on the first interconnection pattern in which the first differential coil serves as a reference coil and the second differential coil serves as a sensing coil, and the electronic components are provided in the second interconnection pattern but are not provided in the first interconnection pattern to enable a circuit based on the second interconnection pattern in which the second differential coil serves as a reference coil and the first differential coil serves as a sensing coil.