A palm mechanism for a high-speed robot hand has a fixed-side articulated finger unit that projects forward from an upper side of a vertically positioned palm plate, and moveable-side articulated finger units disposed on both sides thereof. The left and right articulated finger units are capable of turning along two short sides of the rectangular palm plate from upper end positions on the palm mechanism. The articulated finger units are capable of bending up and down about joint portions thereof. A variety of operations, including gripping, picking, and throwing, can be performed rapidly and reliably by controlling relative positions of the three articulated finger units and controlling bending operations of the articulated finger units.