PURPOSE: To move a shelf back and forth by sliding a sliding rib on both ends of the rear of the shelf along a guide groove of a frame, and to move the shelf and a frame up and down by turning a dial to rotate a driving gear.

CONSTITUTION: When a shelf 1 of a shelf device is moved back and forth, a sliding rib 1a of the shelf 1 is slid along a guide groove 2c of a frame 2. When the shelf 1 is pulled out up to the forefront, the sliding rib 1a strikes on a stopper, causing the shelf not to be pulled forth further. When the shelf 1 is moved up or down, a dial 6 is turned to rotate a dial shaft 7 and a driving gear 8. A driven gear 9 engaging with the driving gear 8 is rotated, causing a gear shaft 4 and plain gears 5 on both side to be rotated. At this time, although the plain gears 5 on both right and left sides are moved by the gear shaft 4 while they engage with racks 14b, the plain gears 5 are identically rotated as they are fixed on the gear shaft 4. As a result, the frame 2, that is, the shelf 1 is evenly moved up or down without a tilt to the right or left side.