A gradient sensor of a component of a magnetic field comprising at least one elementary sensor comprising a deformable mass (31) equipped with a permanent magnet (32) having a magnetization direction substantially colinear to the direction of the gradient of the component of the magnetic field to be acquired by the sensor. The deformable mass (31) is able to deform under the effect of a force exerted on the magnet by the gradient, the effect of this force being to shift it, by dragging the deformable mass (31), in a direction substantially colinear to the component of the magnetic field for which the sensor has to acquire the gradient. The deformable mass (31) is anchored to a fixed support device (33) in at least two anchoring points (36) substantially opposite relative to the mass (31). The elementary sensor also comprises measuring means (35, 35.1, 35.2, 35.3) of at least one electric variable translating deformation or stress of the deformable mass (31) engendered by the gradient.