Retaining device for holding a boot on a gliding board, the retaining device comprising: - a chassis configured to cooperate with a complementary retaining element formed by an interface plate that is secured to the gliding board or with a complementary retaining element bearing guiding and retaining rails which are formed directly by the gliding board so as to be able to slide longitudinally relative to the gliding board, the chassis having an underside face intended to face towards the gliding board and extending mainly along a plane referred to as main plane, - a holding mechanism configured to cooperate with a latching element belonging to the boot in order that the boot is held in position relative to the chassis, the holding mechanism being borne by the chassis, - an adjusting member configured to collaborate with a rack secured to the gliding board such that actuation of the adjusting member causes the chassis to slide longitudinally with respect to the gliding board, the adjusting member comprising a collaboration portion mounted for rotation about an axis of rotation, the collaboration portion comprising an underside face bearing at least a first relief having two lateral flanks (X1, X2) extending respectively in a curved path shaped in such a way that the distance between a point on one of these paths and said axis of rotation varies progressively all along at least part of the curved path, the first relief being configured in such a way that the lateral flanks (X1, X2) thereof are able to collaborate with contact surfaces (Y1, Y2) of complementary reliefs of the rack so as to cause the chassis to slide longitudinally with respect to the gliding board under the effect of the rotation of the collaboration portion about said axis of rotation, characterized in that the adjusting member is borne by the chassis and in that the axis of rotation is inclined by an angle (alpha) of between 30° and 90° with respect to said main plane in which the underside face of the chassis chiefly extends. - a chassis configured to cooperate with a complementary retaining element formed by an interface plate that is secured to the gliding board or with a complementary retaining element bearing guiding and retaining rails which are formed directly by the gliding board so as to be able to slide longitudinally relative to the gliding board, the chassis having an underside face intended to face towards the gliding board and extending mainly along a plane referred to as main plane, - a holding mechanism configured to cooperate with a latching element belonging to the boot in order that the boot is held in position relative to the chassis, the holding mechanism being borne by the chassis, - an adjusting member configured to collaborate with a rack secured to the gliding board such that actuation of the adjusting member causes the chassis to slide longitudinally with respect to the gliding board, the adjusting member comprising a collaboration portion mounted for rotation about an axis of rotation, the collaboration portion comprising an underside face bearing at least a first relief having two lateral flanks (X1, X2) extending respectively in a curved path shaped in such a way that the distance between a point on one of these paths and said axis of rotation varies progressively all along at least part of the curved path, the first relief being configured in such a way that the lateral flanks (X1, X2) thereof are able to collaborate with contact surfaces (Y1, Y2) of complementary reliefs of the rack so as to cause the chassis to slide longitudinally with respect to the gliding board under the effect of the rotation of the collaboration portion about said axis of rotation,