Abstract: The present invention provides a workpiece-transfer device that has functions for both loading and unloading workpieces, without requiring a workpiece-storage device to enable a function for replacing material and product workpieces with each other, and that requires only a simple configuration and low costs. A workpiece-transfer device loads a material workpiece W1 in a workpiece-machining device 1 and unloads a product workpiece W2 from the workpiece-machining device 1. A movement means with a rectangular coordinate system 30 is provided to move a traveling body 27 in a first direction along the direction in which the workpiece-machining device 1 and a workpiece-storage device 2 stand in a line (direction X) as well as in a second horizontal direction orthogonal to the first direction (direction Y). The traveling body 27 includes a gripping means 28 for gripping a material or product workpiece W1 and W2.