A workpiece feeder for successively feeding workpieces to a predetermined workpiece gripping station of the robot's hand. The workpiece feeder includes a conveyor having a plurality of interspaced pallets traveling on a table. Each pallet comprises a lower plate having a central opening and an upper plate which is detachably mounted on the lower plate. The workpiece feeder is provided with a lifting means having a vertically movable platform which ascends through the central opening in the lower plate to lift the upper plate away from the lower plate, thereby elevating the workpiece on the pallet up to the level of the gripping position of the robot's hand. The workpiece feeder further comprises a stop mechanism for limiting the topmost position of the platform. The workpiece feeder according to the invention is particularly suitable for use with an industrial robot of the simplified type in which the upright stand enabling the robot's hand to perform vertical translational movement is omitted.