PURPOSE: To safely, smoothly slide a shelf without lifting or falling off from a frame even when a lot of foods loaded on the shelf, by providing the frame which has support members and supports the shelf on which a reinforcing plate is attached, guide planes which guide sliding members attached on the frame, and rails having rack faces.

CONSTITUTION: When a dial 6 is turned to move a shelf 1 up or down, plain gears 5 on both sides is rotated, so that a frame 2, that is, the shelf 1 is moved up or down without a tilt and no difference of the level between the left and right sides occurs. Therefore, sliding members 3 which move up or down along guide planes 14a smoothly slide without tilting or generating an abnormal sound, resulting in less turning force of the dial 6. As protrusions la on both side walls of the shelf 1 are inserted in grooves 2f formed on the frame 2 through cut parts 2g, the shelf 1 is freely pulled out and the ends of grooves 2f serve as stoppers. Moreover, when the shelf 1 is moved up or down, the shelf 1 can be prevented from lifting or falling off due to foods on a low shelf, and reinforcing plate 20 provided on the front rear face of the shelf 1 prevent s the shelf from being bent, so that a lot of food can be loaded on the shelf.