A workpiece picking device configured to pick up plate-like or pillar-shaped workpieces one at a time from the top of the workpieces stacked in the vertical direction, the workpiece picking device including: a chuck including a plurality of gripping claws arranged around the topmost workpiece and configured to grip a side surface of the topmost workpiece, and movable in a vertical direction, and a separator provided inside at least one of the gripping claws, and configured to separate the topmost workpiece gripped by the plurality of gripping claws from the second workpiece, the separator including a pressing part configured to be projectable downwardly from the at least one of the gripping claws toward the second workpiece, and a driving part configured to press the pressing part against the second workpiece by moving the pressing part toward the second workpiece.