To provide a workpiece supply/conveyance device that can remove a workpiece from and supply a workpiece to a spindle smoothly in a short time.

In the workpiece supply/conveyance device 2 including a plurality of arms 24 extended from rotational centers to a radial direction and freely rotatably holding workpieces integrally with the rotational centers as centers and performing the supply/conveyance of workpieces together with a workpiece machining device 1 when an arm 24 holding an unprocessed workpiece is positioned in a workpiece transfer position I, the rotational direction of each arm 24 is set in one direction so as to move in order to an unprocessed workpiece loading position III for receiving the unprocessed workpiece to a workpiece transfer position I and to a processed workpiece unloading position II at which the processed workpiece is unloaded, and in each arm 24, an unprocessed workpiece holding part 29 is provided at the upstream side in the rotation direction and a processed workpiece holding part 21 is provided at the downstream side in the rotation direction so that the processed workpiece may be received from the workpiece machining device 1 by rotation in one direction of the arm 24 in the workpiece transfer position I and the unprocessed workpiece may be delivered to the workpiece machining device 1.