To provide a supporting device capable of holding a plate-like movable body at an optional position at a prescribed rotating angle.

This supporting device is provided with a rack 13 provided for the supporting body, a gear case 14 fitted with the rack 13 to house a gear 15 rotating linked with the vertical movement of the supporting body, a supporting axis 23 provided at the width direction tip part of a movable body 11 to be supported by the gear case 14 in the state of being freely rotatable, and a first stopper 25 provided on the side face of the gear case 14. In addition the supporting device is provided with a second stopper 26 provided at a position corresponding to side face of the gear case 14 of the movable body and abutted on the stopper 25 to hole the movable body at a prescribed rotating angle at the time of rotating the movable body by a supporting axis, and gears 16 and 17 preventing the rotation of a gear to hold the body 11 at optional height positions at the time of rotating the body 11 and holding at a prescribed angle.