Abstract: The device is comprised of a plate (2) secured to a wall (3) and exhibiting an engagement recess (12) into which an end portion (11) of a supporting arm (8) on which the shelf (10) is mounted, is oscillatably introduced. An adjusting cam member (15) operable through a hole (25) formed in the shelf (10) acts between the supporting arm (8) and the plate (2) for adjusting the arm inclination and therefore the shelf inclination in a transverse direction. A set pin (21) acts between the plate (22) and the cam element (15) for adjusting the vertical positioning of the arm and therefore the shelf inclination in a longitudinal direction.