by the supporting links 60 in which the engaging hooks 62 of the supporting links 60 facing each other inward the holders 100 at the both sides are rotatably inserted into the bores 52 provided on the front and rear locations at the both sides of the tray 50 when the tray 50 is installed at the lower ends of the supporting links 60 in such a way the tray 50 is in close contact with the ceiling surface c of the storage space by means of the elastic forces of the elastic members 90 as shown in fig3 a at this time since the supporting links 60 are also rotated therewith to be urged to the ceiling surface c of the storage space the connecting links 70 connected to opposite ends of the supporting links 60 are in the rotated state shown in fig3 a such rotation is achieved by the elastic forces of the elastic members 90 therefore the interlocking links 80 have been moved to a relatively left position as viewed in the figure meanwhile in order to lower the tray 50 a user merely grasps the downwardly sloped portion 54 formed at the front end of the tray 50 and exerts a force on the sloped portion so that the tray is moved downward and rearward when the user exerts the force on the tray 50 the link mechanisms that support the tray 50 are pivoted while overcoming the elastic forces of the elastic members.