Abstract: The invention relates to a permanent magnet.Seen in profile, said permanent magnet 6, which has its North and South poles N 6, S 6 along one and the same line 7 radial to its axis of rotation 4, has contours 21, 22 on the areas 23, 24 which carry said poles; the contours being, with respect to the axis of rotation 4: on the one hand, diametrically opposed; and on the other hand, situated at different distances from said axis 4, the fractions 23a, 24a on the one hand, and 23b, 24b on the other hand, of said zones being distanced differently depending on whether they are to one side or the other of the aforementioned radial line 7.Application to bistable elements and to data display units consisting in at least one such bistable element.